ks3 science forces 1 - rastrick high school€¦ · ks3 science forces 1 name: _ class: _...

KS3 ScienceForces 1

Name: _____________________________Class: _____________________________Teacher: ___________________________

In this topic you will learn about:• Speed and Relative motion• Distance time graphs• Different types of forces• Weight, Mass and GravityPractical Skills: • Assessed Enquiry – Speed down a rampThis will prepare you for:• GCSE physics topic ‘Forces A & Forces B’This topic has links to• Y8 forcesMaths in science: • Rearranging Equations• Plotting Graphs

Key Words:SpeedAccelerationDecelerationRelative MotionForceStationary Constant MotionWeightMass GravityAir resistanceReaction forceUpthrust

Contents:

Booklet Expectations:

The booklet is your responsibility to look after and keep tidy.

You are expected to bring the booklet to every lesson with that class teacher.

Any corrections / self assessment to be completed in green pen, as indicated by your class teacher – Or when you see the ‘feedback & assessment’ logo

Any response to marking and literacy codes to be completed in green pen.

Any diagrams are to be drawn in pencil, graphs using a pencil and ruler etc.

All activities are to be completed, including homework, to the best of your ability, and corrected where needed.

When reading through the notes, you are expected to highlight any words you do not understand, then write their definitions on the glossary pages at the back of the booklet.

Lesson 1: Understanding speedLesson 2: Distance time graphsLesson 3: Exploring Journeys on Distance time graphsLesson 4: Assessed Enquiry Investigating motion of a car on a rampLesson 5: Relative MotionLesson 6: Different ForcesLesson 7: Mass, Weight and GravityRevisionStudent made Glossary

ANSWERS AT BACK OF BOOKLET

Week commencing 7th Dec – 18th Jan2 lessons per week

Lesson 1: Understanding speed

In and On: Write down any questions you have about speed

Learning outcomes:• List the factors involved in defining speed. • Describe a simple method to measure speed • Use and apply the speed formula.

How far could you travel going 60mph and 50 mph in…

a) 1 hour?b) 2 Hours?c) 5 Hours?d) 30 minutes?

Speed is ____________________________________________

In science the units we use areDistance – meters (m)Time – Seconds (s)Speed – Meters per second (m/s)

Use the formula triangle above to calculate speed:

a) 100 m in 20 seconds

b) 48 m in 4 seconds

c) 57 m in 3 seconds

d) 3 km in 100 seconds

e) 1 km in 1 minute

f) 350 km in 5 hours

Challenge: Calculate distance travelled in km when speed is 50m/s and the car has been travelling for 3 hours.

Practical:Aim: calculate the speed of various ways to move

Imagine a normal journey across a town that is 15 km across. The car sets off at 9.00 am and arrives at 11.00 am. During the journey the car reaches a highest speed of 50 km/h but has to slow down for traffic and stop several times at junctions.

a) Work out the overall average speed for the journey.

b) Explain why the average speed is so much lower than the highest speed.

c) Two cyclists, Victoria and Laura, also set off at 9.00 am and head for the same destination as the car. Victoria takes the same route as the car and arrives at 10.30 am. Laura takes the ring road, which is a distance of 22 km, and arrives at 10.15 am. Work out the average speeds of the two cyclists.

d) Suggest reasons why Laura arrived first despite taking the longer route.

Challenge task: Average speedsRead the information & complete the questions.

Additional notes:________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Learning outcomes review:

• List the factors involved in defining speed.

• Describe a simple method to measure speed

• Use and apply the speed formula.

Key Vocab:

Speed limits are enforced in the UK.Write down reasons why these are important.Why can you go faster on the motorway than in an urban area?

Lesson 2: Distance time graphs

In and On: Look at the picture of the graph. Discuss with a partner what you think this represents.

Learning outcomes:• Gather relevant data to describe a journey.• Use the conventions of a distance–time graph.• Display the data on a distance–time graph.

A journey can be represented using a distance time graph. The graph shows a cyclists journey. 1) What units could measure the cyclists speed?

2) How far did they travel in the first 6 seconds?

3) What was the cyclists speed?

4) Sketch another line to show the journey of a cyclist who is travelling at half the speed.

For each graph below – write a few words to describe the speed of eachSuggestions: Constant speed, stationary, accelerating, decelerating.Challenge: What about the direction of the movement?

Task 1: Write a brief description of each journey shown on the graphs

a) _______________________________________________________________________________________________________________b) ________________________________________________________________________________________________________________c) ________________________________________________________________________________________________________________d) ________________________________________________________________________________________________________________

Time (min) 0 10 15 20 30 40 50 60 70 80 90

Distance travelled by car (km) 0 10 10 15 20 40 60 65 70 75 80

Distance travelled by train (km) 0 20 30 40 40 60 80 80 80 80 80

Task 2: On the same graph, plot a distance time graph for each journey

From your graph, answer these questions:Identify the times when:

i) the car was not moving __________________

ii) the train was not moving. __________________

What was the total journey time for:

i) the car ___________________

ii) the train? ___________________

Challenge questions:

Calculate the fastest speed in km/h achieved by each mode of transport.

Calculate the average speed in km/h over the entire journey for each mode of transport.

Suggest why one mode of transport has a quicker journey time than the other.

Plenary: Complete the sentences:A horizontal line on a distance-time graph shows ________________________.

The steeper the line on the graph, _______________________.

A curved line shows ____________________________.

Options: Faster the speed / Object is stationary / acceleration or deceleration



Key Vocab:

• Gather relevant data to describe a journey.

• Use the conventions of a distance–time graph.

• Display the data on a distance–time graph.

Lesson 3: Exploring journeys on distance-time graphs

In and On: Solve the anagrams:

Deeps: _________ Ratgiend: _________ Veeraag: ___________

Learning outcomes:• Interpret distance–time graphs to learn about the journeys represented.• Relate distance–time graphs to situations & describe what they show.

Task 1: Work out the missing values, use the triangle to help

Distance = 130 miles

Speed = ? mph

Time = 2 hours

Distance = ? Km

Speed = 13 km/h

Time = 3 hours

3. Distance = 48 m

Speed = 4 m/s

Time = ? Seconds

Distance = 60 miles

Speed = ? mph

Time = 30 minutes

Distance = 20 km

Speed = ? km/h

Time = 15 minutes

Task 2: Can you match the pictures with their respective graphs?

Challenge: Explain your choices:

AccelerationOn a distance–time graph, a _____ slope shows that an object is travelling _______ than an object with a shallow slope. If the object rapidly _________, the slope of the line will change rapidly. However, if the change in speed is more gradual, the _______will change more gradually.

Which object has the fastest starting speed? _____

Which object has the fastest final speed? _____

Task 3: Write a short story describing each graph:

______________________________________________________________________________________________________

______________________________________________________________________________________________________

______________________________________________________________________________________________________

Task 4: Complete the following questions: The distance–time graph shows the journey of a tennis ball rolling down a ramp and across the floor.

a) Label the curve to show:

i) where the ball is travelling fastest

ii) where the ball is accelerating

iii) where the ball is slowing down

iv) where the ball is stationary.

b) Explain why the ball speeds up for part of its journey and slows down for part of its journey.

________________________________________________

Imagine it took 10 seconds from the moment the ball was released to when it finally came to rest. If the motion was videoed and the recording was

stopped after each second, we would see the position of the ball at one-second intervals.

The diagram shows the position of the ball at 0 seconds, 1 second,

2 seconds and 3 seconds, as it rolls down the ramp. Show where you would expect the ball to be at each interval between 4 seconds and 10 seconds.

2.The distance–time graph shows the journey of a golf ball from the tee to the hole.

Use the graph to answer the

following questions.

a) How many shots did the golfer

take? ………………….

b) What was the total distance

travelled by the ball?

………………….

c) How far did the golfer’s longest

shot go? ………………….

Four sections of the graph are curved rather than straight. Explain what this shows.

________________________________________________________________________________________________________________________________________________________________________________________________________________________________

There are different types of speed cameras. Some measure the mean (average) speed of a car over a certain distance, such as a kilometre or a mile. They do this by timing how long it takes for a car to cover the distance and then using the speed formula to calculate the mean speed.Using a worked example, explain how a camera calculates the mean speed

over a set distance.

Plenary: Use the graph to answer the questions:



Key Vocab:

• Interpret distance–time graphs to learn about the journeys represented.

• Relate distance–time graphs to situations & describe what they show.

How long did he stop for?

What was his speed for the first hour?

How long did it take him to run 40km?

Lesson 4: Assessed EnquiryInvestigating motion of a car on a ramp

In and On: What are the 3 types of variables?:

• Learning outcomes:• Describe the motion of an object whose speed is changing.• Devise questions that can be explored scientifically.• Present data so that it can be analysed to answer questions.

Watch the teacher demo and answer the following questions:Explain why the car accelerates down the ramp:

_______________________________________________________________

_______________________________________________________________

Explain why the car decelerates once it reaches the ground:

_______________________________________________________________

_______________________________________________________________

Challenge: Why do the forces in the first part of the journey make it accelerate and those in the second part make it decelerate?

_______________________________________________________________

_______________________________________________________________

_______________________________________________________________

_______________________________________________________________

Practical: Investigating motion of a car on a ramp

Hypothesis: The ___________ the ramp, the ____________ the distance travelled by the car.

Variables:

Independent Variable: _____________________________________

Dependent Variable: ______________________________________

Control Variable(s): _______________________________________

_______________________________________________________

Method:For your first height, place the car at the top of the ramp. Let it go, and then record the distance it travels from the bottom of the ramp to where it stops. Repeat this twice more, then increase the height. Keep doing this until you have reached the maximum height.Calculate the mean distance travelled by the car for each heightPlot your results as a line graph on the next page

Height of ramp (m)

Distance travelled by the car (m)

Try 1 Try 2 Try 3 Mean

Results table:

Describe the pattern shown on the graph.

_________________________________________________________

_________________________________________________________

_________________________________________________________

Write a conclusion of your results – what did you find?

_________________________________________________________

_________________________________________________________

_________________________________________________________

Explain your findings – link this to your knowledge of forces

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

Why was a line graph the most appropriate graph for this experiment?

_________________________________________________________

_________________________________________________________Evaluate the experiment – did anything go wrong? Why? Is your data reliable? How could you improve the practical?_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

_________________________________________________________

Lesson 5: Relative motion

In and On: Which one of the below speeds is the fastest?30 m/s1800 m/minute108,000 m/hour946,080,000 m/year

Learning outcomes:• Describe the motion of objects in relation to each other.• Explain the concept of relative motion.• Apply the concept of relative motion to various situations.

Define relative speed:

Answer the questions on relative speed using the example below:A person sets off jogging along a canal path at 12 km/h at the same time as a boat sets off at 10 km/h.a) How far will each one travel in half an hour?_______________________________________________________b) What is their relative speed?_______________________________________________________c) To the jogger, how would the boat appear to be moving as they travel along the canal?_______________________________________________________

Time (minutes)

Distance (km) CAR A

Distance (km)CAR B

0 0 0

2 2 0

4 4 4

6 6 8

8 8

Task: On the next page, plot a graph of the data in the table.This will need to be 2 lines drawn on the same graph. Then answer the questions that follow based on your graph.

Which car set of the latest?

If they were in the same lane when would they crash?

Which car finished their journey first?

Which car had the fastest speed?

What is their relativistic speed?

Challenge Question – Why are head on collisions so dangerous?

Task 1:

The diagrams show two cars travelling along a road in the same direction. The cars are travelling at different but constant speeds. Picture 2 is taken 10 secs after picture 1.

a) How far has each car travelled between picture 1 and picture 2? _____________________________________________________________b) Calculate the speed of each car in m/s

_____________________________________________________________

c) What is the relative speed of the two cars?

____________________________________________________________d) How far apart will the two cars be after a further 5 seconds has passed?_____________________________________________________________

e) Add a third car to the diagram above, which starts 10 m ahead of car A, but travels at half the speed of car A.

Task 2: Two cars are driving along a road in the same direction. The car in front, driven by Alex, is travelling at a steady speed of 15 m/s. The car following, driven by Georgie, is catching up and is travelling at 20 m/s. Draw a diagram similar to the one in task 1, to show an 800 m stretch of road. The faster car is 100 m from the start. The slower car is 100 m ahead. Mark the position and direction of travel of the two cars.

b) Georgie’s car pulls alongside Alex’s car

20 s after the diagram in part a). What position on the stretch

of road will they have reached?

c) Draw a second diagram to show the new position of each car when Georgie is alongside Alex.

Challenge: A third car is driven by Asma and is travelling in the opposite direction to Georgie and Alex. It starts at the far end of the end of the 800 m stretch of road and is travelling at 10 m/s.

a) Add the position of Asma’s car to the two diagrams you drew in task 2.

b) If all cars continue at their same speeds, Could Georgie overtake safely?

c) What advice would you give to Georgie about overtaking?

d) Add to both diagrams a police car that is rushing to an emergency. It is travelling in the same

direction as Alex and Georgie at a speed of 40 m/s. In the first diagram it is 100 m behind Georgie.

e) Suggest why police emergency response drivers need to be very highly trained.

Plenary: Which scenario is worse? Explain your answer:



Key Vocab:

• Describe the motion of objects in relation to each other.

• Explain the concept of relative motion.• Apply the concept of relative motion to

various situations

a) A car travelling at 10 km/h and colliding with a parked car.b) A car travelling at 70 km/h and colliding with a car going 60 km/h in the same direction.c) A car travelling at 70 km/h and colliding with a car doing 60 km/h in the opposite direction.

Lesson 6: Different Forces

In and On: How many different forces can you name?

• Learning outcomes:• Recognise different examples of forces.• List the main types of force.• Represent forces using arrows.

What 3 things can a force do?

A force is: _______________________________________________

• Weight

• Upthrust

• Friction

• Air Resistance

• Lift

• upward force exerted on an object in a fluid

• resistive force due to moving through air

• resistive force due to 2 objects in contact

• force that uses motion to make an object rise up

• downwards force due to gravity

Task: Match the force to what it does

Task: Add arrows to show the forces acting on a person who is stationary

Task: Add arrows to show the forces acting on a car which is travelling at a constant speed

Add force arrows to show the correct forces acting on each object.Chose from the options below:Weight Friction Upthrust Reaction

Lift Forward force Air resistance

If forces are balanced, an object will be _______________ or travelling at a __________ speed. Unbalanced forces lead to a change in ______ (acceleration or deacceleration) or in ______________.

Task: Show arrows on each diagram below for the different scenarios

Team A pulls to the left and team B pulls to the right with the same-sized forces.

Team B pulls with a larger force Team A pulls with a larger force

Describe in words what happens in a tug-of-war when:

i) the forces are balanced

________________________________________________________________________

_________________________________________________________________________

ii) the forces are unbalanced.

_________________________________________________________________________

_________________________________________________________________________

2. A tennis player hits a ball using a racket. Think about the forces acting on the ball at different stages of a tennis match and answer these questions.

a) Explain how the ball can still be moving when it is no longer in contact with the racket.

_________________________________________________________________________

_________________________________________________________________________

b) What forces act on the ball during its flight?

_________________________________________________________________________

_________________________________________________________________________

c) When a ball has rolled to a stop, what forces (if any) are acting?

_________________________________________________________________________

_________________________________________________________________________

Challenge: Forces are at work when a firework rocket is set off. Describe and explain the forces involved during the flight of the rocket

Plenary: Add arrows to the two plane. The first is at a constant height and speed, the second accelerating towards the ground



• Recognise different examples of forces.

• List the main types of force.

• Represent forces using arrows.

Key Vocab:

Lesson 7: Weight, Mass and gravity

In and On: What is mass? What is weight? Are they the same thing? Explain

Learning outcomes:• Describe gravity as a non-contact force.• Explore the concepts of gravitational field and weight.• Explain how weight is related to mass.

Mass is: _________________________________________________

________________________________________________________

Weight is: _______________________________________________

________________________________________________________

Gravity is: _______________________________________________

________________________________________________________

Weight = ______ x ______ (weight measured in ___)Mass = ________ / _____ (mass measured in ____)Gravity = ______ / _____ (gravity measured in ____)

An astronaut has a mass of 80 kg. When will he weigh more? Earth – g = 10N/kg Moon – g = 1.5N/kg

The gravitational field strength on earth is around 10 N/kg. What is your weight if your mass is 45 kg?

My mass is __________. On earth my weight is _______. (g = 10N/kg)

On Mars, gravity is 4 N/kg.

If I lived on Mars my MASS would be ………………… kg.

If I lived on Mars my WEIGHT would be ………………… N.

Planet My mass Gravity My weight

Mercury kg 4 N/kg N

Venus kg 9 N/kg N

Earth kg 10 N/kg N

Mars kg 4 N/kg N

Jupiter kg 25 N/kg N

Saturn kg 10 N/kg N

Uranus kg 9 N/kg N

Neptune kg 11 N/kg N

Complete the table:Does your mass change?

Does your weight change?

Where do you weigh the most? Least?

Decide which of the following statements are true and which are false.

Rewrite the false ones to change them into true statements.

a) The weight of an object is always the same.

b) Weight is a force, so it is measured in newtons.

c) The mass of an object depends on the strength of the gravitational field.

d) Gravitational field strength gets weaker the further you are from the object causing it.

e) The Earth’s gravitational field reaches to the edge of the atmosphere but no further.

___________________________________________________________________________________________________________________________________________________________________________

Use your knowledge about matter, gravitational field strength and forces to explain why, for a particular object, mass does not vary but weight does.

___________________________________________________________________________________________________________________________________________________________________________

Imagine a mouse and an elephant falling towards the Earth. Calculate the force due to gravity and the acceleration due to gravity for the mouse with a mass of 100 g and for the elephant with a mass of 5000 kg. Assume that air resistance has no effect. Where it helps, draw diagrams to explain your answer.

Plenary: Mini Quiz!! Write true or False

1) Mass is measured in grams and kilograms.

2) Weight is the same as mass.

3) The moon orbits the sun.

4) Gravitational forces change on other planets.

5) Earth orbits the sun every 24 hours.

6) You weigh less on the moon.

7) Your mass changes in space



• Describe gravity as a non-contact force.

• Explore the concepts of gravitational field and weight.

• Explain how weight is related to mass.

Key Vocab:

RevisionThe next 2 pages are left blank for you to use for revision in preparation for the end of topic test.Your teacher may ask you to complete a specific revision activity or ask you to revise independently.Suggested activities include: Mind maps, practice questions from the text book, flash cards, memorising key words and concepts.

Glossary: Throughout the topic – use this page to make not of key words and their meanings. This can be a revision aid.

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Speed is ____________________________________________







e) 1 km in 1 minute



50 x 1 = 50 miles50 x 2 = 100 miles50 x 5 = 250 miles

50 x 0.5 = 25 miles

The distance travelled in a certain time

100 ÷ 20 = 5 m/s

48 ÷ 4 = 12 m/s

57 ÷ 3 = 19 m/s

3000 ÷ 100 = 30 m/s

1000 ÷ 60 = 16.7 m/s

350 ÷ 5 = 70 km/h






Speed is ____________________________________________







e) 1 km in 1 minute



50 x 1 = 50 miles50 x 2 = 100 miles50 x 5 = 250 miles

50 x 0.5 = 25 miles

The distance travelled in a certain time

100 ÷ 20 = 5 m/s

48 ÷ 4 = 12 m/s

57 ÷ 3 = 19 m/s

3000 ÷ 100 = 30 m/s

1000 ÷ 60 = 16.7 m/s

350 ÷ 5 = 70 km/h

50 x 3 x 60 x60= 540,000 m

Practical:Aim: calculate the speed of various ways to move

Imagine a normal journey across a town that is 15 km across. The car sets off at 9.00 am and arrives at 11.00 am. During the journey the car reaches a highest speed of 50 km/h but has to slow down for traffic and stop several times at junctions.

a) Work out the overall average speed for the journey.

b) Explain why the average speed is so much lower than the highest speed.

c) Two cyclists, Victoria and Laura, also set off at 9.00 am and head for the same destination as the car. Victoria takes the same route as the car and arrives at 10.30 am. Laura takes the ring road, which is a distance of 22 km, and arrives at 10.15 am. Work out the average speeds of the two cyclists.

d) Suggest reasons why Laura arrived first despite taking the longer route.

Challenge task: Average speedsRead the information & complete the questions.

Speed = distance ÷ time 15 ÷ 2 = 7.5 km/h

The car’s speed is slower than the top speed for some of the journey and this decreases the average value.

VICTORIA Speed = distance ÷ time 15 ÷ 1.5 = 10 km/h

LAURA Speed = distance ÷ time 22 ÷ 1.25 = 17.6 km/h

Laura didn’t stop at junctions or Laura is fitter than Victoria



• List the factors involved in defining speed.

• Describe a simple method to measure speed

• Use and apply the speed formula.

Key Vocab:

Speed limits are enforced in the UK.Write down reasons why these are important.Why can you go faster on the motorway than in an urban area?

Slower speeds are safer. Drivers have more time to react to incidents. Collisions at slower speeds cause fewer injuries and fewer deaths.Motorways are straighter and flatter. Visibility is better. They have fewer turns with smaller turning angles. Lanes are wider so there is more room for vehicles to pass each other.

SpeedDistanceTimeCollisionFasterSlower

Lesson 2: Distance time graphs

In and On: Look at the picture of the graph. Discuss with a partner what you think this represents.

Learning outcomes:• Gather relevant data to describe a journey.• Use the conventions of a distance–time graph.• Display the data on a distance–time graph.

A journey can be represented using a distance time graph. The graph shows a cyclists journey. 1) What units could measure the cyclists speed?

2) How far did they travel in the first 6 seconds?

3) What was the cyclists speed?

4) Sketch another line to show the journey of a cyclist who is travelling at half the speed.

For each graph below – write a few words to describe the speed of eachSuggestions: Constant speed, stationary, accelerating, decelerating.Challenge: What about the direction of the movement?

m/s

30 m

Speed = distance ÷ time 30 ÷ 6 = 5 m/s

stationary Constant speed forward

Constant speed backwards

Speeding up (accelerating)

Slowing down (decelerating)

Constant speed forward (slower than B)

Task 1: Write a brief description of each journey shown on the graphs

a) _______________________________________________________________________________________________________________b) ________________________________________________________________________________________________________________c) ________________________________________________________________________________________________________________d) ________________________________________________________________________________________________________________

Time (min) 0 10 15 20 30 40 50 60 70 80 90

Distance travelled by car (km) 0 10 10 15 20 40 60 65 70 75 80

Distance travelled by train (km) 0 20 30 40 40 60 80 80 80 80 80

Task 2: On the same graph, plot a distance time graph for each journey

From your graph, answer these questions:Identify the times when:

i) the car was not moving __________________

ii) the train was not moving. __________________

What was the total journey time for:

i) the car ___________________

ii) the train? ___________________

Constant speed forward then stationary (stopped)

Constant speed forward (slow) then constant speed forward (fast) then stationary (stopped)

Constant speed forward

Speeding up (accelerating) then slowing down (decelerating) then stopped (stationary)

Between 10 and 15 mins

Between 20 and 30 mins and after 50 mins

90 mins

50 mins

Challenge questions:

Calculate the fastest speed in km/h achieved by each mode of transport.

Calculate the average speed in km/h over the entire journey for each mode of transport.

Suggest why one mode of transport has a quicker journey time than the other.

Time (min)

Dis

tan

ce t

rave

lled

(km

)

20 40 60 80

20

40

60

80

X

XXXX

X

X X

X

X

XXX

X

X

X

X

X

XX car

train

The car has to travel slowly in town, stopping for traffic lights and in congestion.The train has fewer delays and stops at stations.

CAR Speed = distance ÷ time 80 ÷ 90 = 0.89 km/min

TRAIN Speed = distance ÷ time 80 ÷ 50 = 1.6 km/min

#1

#2

CAR #1 Speed = distance ÷ time (60-20)÷(50-30) = 2 km/min TRAIN #2 Speed = distance ÷ time (80-40)÷(50-30) = 2 km/min

Plenary: Complete the sentences:A horizontal line on a distance-time graph shows ________________________.

The steeper the line on the graph, _______________________.

A curved line shows ____________________________.

Options: Faster the speed / Object is stationary / acceleration or deceleration



Key Vocab:

• Gather relevant data to describe a journey.

• Use the conventions of a distance–time graph.

• Display the data on a distance–time graph.

Object is stationary (stopped)

the faster the speed

Acceleration or deceleration (changing speed)

AccelerationDeceleration

AcceleratingDecelerating

stationary

Lesson 3: Exploring journeys on distance-time graphs

In and On: Solve the anagrams:

Deeps: _________ Ratgiend: _________ Veeraag: ___________

Learning outcomes:• Interpret distance–time graphs to learn about the journeys represented.• Relate distance–time graphs to situations & describe what they show.

Task 1: Work out the missing values, use the triangle to help

Distance = 130 miles

Speed = ? mph

Time = 2 hours

Distance = ? Km

Speed = 13 km/h

Time = 3 hours

3. Distance = 48 m

Speed = 4 m/s

Time = ? Seconds

Distance = 60 miles

Speed = ? mph

Time = 30 minutes

Distance = 20 km

Speed = ? km/h

Time = 15 minutes

Task 2: Can you match the pictures with their respective graphs?

Challenge: Explain your choices:

speed gradient average

130 ÷ 2 = 65 mph 13 x 3 = 39 km 48 ÷ 4 = 12 s

60 ÷ 0.5= 120 mph

20 ÷ 0.25= 80 km/h

A

E

B

D

C

AccelerationOn a distance–time graph, a _____ slope shows that an object is travelling _______ than an object with a shallow slope. If the object rapidly _________, the slope of the line will change rapidly. However, if the change in speed is more gradual, the _______will change more gradually.

Which object has the fastest starting speed? _____

Which object has the fastest final speed? _____

Task 3: Write a short story describing each graph:

Task 4: Complete the following questions: The distance–time graph shows the journey of a tennis ball rolling down a ramp and across the floor.

a) Label the curve to show:

1. where the ball is travelling fastest

2. where the ball is accelerating

3. where the ball is slowing down

4. where the ball is stationary.

b) Explain why the ball speeds up for part of its journey and slows down for part of its journey.

steep

fasteraccelerates

gradient

B

C

A person drives a friend’s house at constant speed, stops for an hour and drives home at constant speed.

A bus leaves school at drives at constant speed to a museum. Pupils visit for 1 hour. The return journey takes 30min.

A cyclist rides home fast for 15 mins. She stops for 30min for lunch. She rides slowly back for the remaining 12km.

2

1

3

4

Gravity makes the ball speed up as it goes down the ramp

Friction makes the ball slows down as it moves over the floor

Imagine it took 10 seconds from the moment the ball was released to when it finally came to rest. If the motion was videoed and the recording was

stopped after each second, we would see the position of the ball at one-second intervals.

The diagram shows the position of the ball at 0 seconds, 1 second,

2 seconds and 3 seconds, as it rolls down the ramp. Show where you would expect the ball to be at each interval between 4 seconds and 10 seconds.

2.The distance–time graph shows the journey of a golf ball from the tee to the hole.

Use the graph to answer the

following questions.

a) How many shots did the golfer

take? ………………….

b) What was the total distance

travelled by the ball?

………………….

c) How far did the golfer’s longest

shot go? ………………….

Four sections of the graph are curved rather than straight. Explain what this shows.

________________________________________________________________________________________________________________________________________________________________________________________________________________________________

There are different types of speed cameras. Some measure the mean (average) speed of a car over a certain distance, such as a kilometre or a mile. They do this by timing how long it takes for a car to cover the distance and then using the speed formula to calculate the mean speed.Using a worked example, explain how a camera calculates the mean speed

over a set distance.

0 1 2 34 5 6 7 8 9 10

4

460 m

210 m

Shot 1

Shot 2

Shot 3

Shot 4

The speed of the ball is changing. The collision with the golf club makes the ball speed up. Air resistance slows the ball in flight. Friction slows the ball as is rolls on the grass.

1. Measure the start time as the car enters the measured mile.2. Measure the end time as the car finishes the measured mile.3. Calculate the speed using :

speed = distance ÷ time= 1 ÷ (end time – start time)

Plenary: Use the graph to answer the questions:



Key Vocab:

• Interpret distance–time graphs to learn about the journeys represented.

• Relate distance–time graphs to situations & describe what they show.

How long did he stop for?

What was his speed for the first hour?

How long did it take him to run 40km?

8 km

Speed = distance ÷ time 10÷1 = 10 km/h

15 min ( ¼ of an hour)

2 hours 45 min (2 and ¾ hours)

SpeedDistanceFrictionAccelerateAir resistance

Lesson 4: Assessed EnquiryInvestigating motion of a car on a ramp

In and On: What are the 3 types of variables?:

• Learning outcomes:• Describe the motion of an object whose speed is changing.• Devise questions that can be explored scientifically.• Present data so that it can be analysed to answer questions.

Watch the teacher demo and answer the following questions:Explain why the car accelerates down the ramp:

_______________________________________________________________

_______________________________________________________________

Explain why the car decelerates once it reaches the ground:

_______________________________________________________________

_______________________________________________________________

Challenge: Why do the forces in the first part of the journey make it accelerate and those in the second part make it decelerate?

_______________________________________________________________

_______________________________________________________________

_______________________________________________________________

_______________________________________________________________

1. Independent variable2. Dependent variable3. Control variable

Gravity pulls the car down the slope and makes the car speed up.

Friction between the car and the ground makes the car slow down.

On the ramp, gravity pulls the car down the slope and affects the motion of the car.

On the ground, only air resistance and friction with the ground affect the motion of the car.

Practical: Investigating motion of a car on a ramp

Hypothesis: The ___________ the ramp, the ____________ the distance travelled by the car.

Variables:

Independent Variable: _____________________________________

Dependent Variable: ______________________________________

Control Variable(s): _______________________________________

_______________________________________________________

Method:For your first height, place the car at the top of the ramp. Let it go, and then record the distance it travels from the bottom of the ramp to where it stops. Repeat this twice more, then increase the height. Keep doing this until you have reached the maximum height.Calculate the mean distance travelled by the car for each heightPlot your results as a line graph on the next page

Height of ramp (m)

Distance travelled by the car (m)

Try 1 Try 2 Try 3 Mean

Results table:

higher bigger

Height of the ramp

Distance moved after the end of the ramp

Same toy car ,

Same ramp length and same ramp material

0.1

0.2

0.3

0.4

0.5

0.22

0.35

0.45

0.58

0.68

0.25 0.27

0.36 0.34

0.45 0.45

0.52 0.56

0.61 0.63

0.24

0.35

0.45

0.55

0.64

0.1 0.2 0.3 0.4 0.5

Height of ramp (m)

Dis

tan

ce t

rave

lled

by

the

car

(m

)

0.1

0.2

0.3

0.4

0.7

0.6

0.5

X

X

X

X

X

Describe the pattern shown on the graph.

Write a conclusion of your results – what did you find?

Explain your findings – link this to your knowledge of forces

Why was a line graph the most appropriate graph for this experiment?

Evaluate the experiment – did anything go wrong? Why? Is your data reliable? How could you improve the practical?

As the height of the ramp increases, the distance travelled by the car increases.

The graph line is a straight line for ramp heights bigger than 0.2m. More data is needed for heights less than 0.1m. Results for 0.1m and 0.5m have a range of 0.05m so more trys would give a better mean.

The data is continuous. The height of the ramp and the distance travelled can have any value.

A steeper ramp gives more force downwards along the ramp. The friction force with the ramp gets less so the car leaves the ramp at a faster speed and with more energy.

From 0.1m to 0.5m, increasing the height of the ramp increased the distance travelled by the car proportionally (straight line)

Lesson 5: Relative motion

In and On: Which one of the below speeds is the fastest?30 m/s1800 m/minute108,000 m/hour946,080,000 m/year

Learning outcomes:• Describe the motion of objects in relation to each other.• Explain the concept of relative motion.• Apply the concept of relative motion to various situations.

Define relative speed:

Answer the questions on relative speed using the example below:A person sets off jogging along a canal path at 12 km/h at the same time as a boat sets off at 10 km/h.a) How far will each one travel in half an hour?_______________________________________________________b) What is their relative speed?_______________________________________________________c) To the jogger, how would the boat appear to be moving as they travel along the canal?_______________________________________________________

Time (minutes)

Distance (km) CAR A

Distance (km)CAR B

0 0 0

2 2 0

4 4 4

6 6 8

8 8

Task: On the next page, plot a graph of the data in the table.This will need to be 2 lines drawn on the same graph. Then answer the questions that follow based on your graph.

They are all the same actual speed. Each value matches a different unit.

Relative speed is how much faster one object is travelling compared to another object.

Distance = speed x time JOGGER 12 x 0.5= 6km, BOAT 10X0.5= 5km

Jogger is 2km/h faster than the boat

backwards

Which car set off the latest?

If they were in the same lane when would they crash?

Which car finished their journey first?

Which car had the fastest speed?

What is the speed of car B relative to car A ?

Challenge Question – Why are head on collisions so dangerous?

Dis

tan

ce t

rave

lled

(km

)

5

3

1

6

4

2

7

8

654321 87

Time (min)

X

X

X

X

X

Car A

X

X

X

Car B

Car B

4 mins or 4 km

Car B

Car B

Car A speed = 8 ÷ 8 = 1 km/hCar B speed = 8 ÷ 6 = 1.33 km/hCar B speed relative to car A 1.33 – 1 = 0.33 km/h

The relative speed of the collision is both car speeds added together

Task 1:

The diagrams show two cars travelling along a road in the same direction. The cars are travelling at different but constant speeds. Picture 2 is taken 10 secs after picture 1.

a) How far has each car travelled between picture 1 and picture 2? _____________________________________________________________b) Calculate the speed of each car in m/s

_____________________________________________________________

c) What is the relative speed of the two cars?

____________________________________________________________d) How far apart will the two cars be after a further 5 seconds has passed?_____________________________________________________________

e) Add a third car to the diagram above, which starts 10 m ahead of car A, but travels at half the speed of car A.

Task 2: Two cars are driving along a road in the same direction. The car in front, driven by Alex, is travelling at a steady speed of 15 m/s. The car following, driven by Georgie, is catching up and is travelling at 20 m/s. Draw a diagram similar to the one in task 1, to show an 800 m stretch of road. The faster car is 100 m from the start. The slower car is 100 m ahead. Mark the position and direction of travel of the two cars.

b) Georgie’s car pulls alongside Alex’s car

20 s after the diagram in part a). What position on the stretch

of road will they have reached?

c) Draw a second diagram to show the new position of each car when Georgie is alongside Alex.

Challenge:

e) Suggest why police emergency response drivers need to be very highly trained.

Car A

70

40

120

Car B

Car A 70 - 0 = 70 m Car B 120 - 40 = 80 m

Car A speed = 70 ÷ 10 = 7 m/s Car B speed = 80 ÷ 10 = 8 m/s

Relative speed = Speed car B – speed car A 8 – 7 = 1 m/s

Current distance apart (50m) + relative extra (1x5) = 55m

C

C10 + 35 = 45

a) Asma is at the far right-hand end in the first diagram, and 200 m from the right-hand end in the second diagram.

b) Not very likely; there is a risk of a head-on collision in just over 3 s.

c) Overtake as fast as possible; wait for a dual carriageway; be patient; choose not to overtake, because it is unsafe.

d) Police car is at the far left-hand end in first diagram, and at the far right-hand end in the second.

e) They need to be able to judge speed of a car and judge risks well. They must not put the public in danger.

200 400 600 800

200 400 600 800

G A

AG 500m from the left side

Plenary: Which scenario is worse? Explain your answer:

Additional notes:________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


Key Vocab:

• Describe the motion of objects in relation to each other.

• Explain the concept of relative motion.• Apply the concept of relative motion to

various situations

a) A car travelling at 10 km/h and colliding with a parked car.

b) A car travelling at 70 km/h and colliding with a car going 60 km/h in the same direction.

c) A car travelling at 70 km/h and colliding with a car doing 60 km/h in the opposite direction.

Relative speed = moving car speed – parked car speed= 10 – 0 = 10 km/h

Relative speed = car 1 speed (70 km/h) – car 2 speed (60 km/h)= 10 km/h

Relative speed = car 1 speed (70 km/h) – car 2 speed (-60 km/h)= 70 + 60= 130 km/h

RelativeSpeedkm/h

Lesson 6: Different Forces

In and On: How many different forces can you name?

• Learning outcomes:• Recognise different examples of forces.• List the main types of force.• Represent forces using arrows.

What 3 things can a force do?

A force is: _______________________________________________

• Weight

• Upthrust

• Friction

• Air Resistance

• Lift

• upward force exerted on an object in a fluid

• resistive force due to moving through air

• resistive force due to 2 objects in contact

• force that uses motion to make an object rise up

• downwards force due to gravity

Task: Match the force to what it does

Task: Add arrows to show the forces acting on a person who is stationary

Task: Add arrows to show the forces acting on a car which is travelling at a constant speed

1. Change object’s speed2. Change object’s shape3. Change moving object’s direction

weight

Reaction from ground Reaction from ground

weight

thrustAir resistance

Add force arrows to show the correct forces acting on each object.Chose from the options below:Weight Friction Upthrust Reaction

Lift Forward force Air resistance

weight

weightweight

weightweight

weight

weightweight

weight

upthrust

upthrustReaction

Reaction

Force up from spring

Force up from hand

Force up from string

reaction

If forces are balanced, an object will be _______________ or travelling at a __________ speed. Unbalanced forces lead to a change in ______ (acceleration or deacceleration) or in ______________.

Task: Show arrows on each diagram below for the different scenarios

Team A pulls to the left and team B pulls to the right with the same-sized forces.

Team B pulls with a larger force Team A pulls with a larger force

Describe in words what happens in a tug-of-war when:

i) the forces are balanced

________________________________________________________________________

_________________________________________________________________________

ii) the forces are unbalanced.

_________________________________________________________________________

_________________________________________________________________________

2. A tennis player hits a ball using a racket. Think about the forces acting on the ball at different stages of a tennis match and answer these questions.

a) Explain how the ball can still be moving when it is no longer in contact with the racket.

_________________________________________________________________________

_________________________________________________________________________

b) What forces act on the ball during its flight?

_________________________________________________________________________

_________________________________________________________________________

c) When a ball has rolled to a stop, what forces (if any) are acting?

_________________________________________________________________________

_________________________________________________________________________

Challenge: Forces are at work when a firework rocket is set off. Describe and explain the forces involved during the flight of the rocket

stationary

constant speed

direction

stationary

Move right Move left

Equal forces act in opposite directions. The rope remains stationary.

Unequal forces act in opposite directions. The rope moves in the direction of the biggest force.

The ball moves at a constant speed in a straight line until another force acts on it and changes its motion.

Air resistance acts in the opposite direction to the direction of motion. Weight acts downwards.

Weight acts downwards. Reaction force upwards from the ground.

1. The rocket moves up because the thrust upwards is bigger than the weight downwards.

2. The rocket slows down because the air resistance force is in the opposite direction to the rocket’s motion.

Plenary: Add arrows to the two plane. The first is at a constant height and speed, the second accelerating towards the ground



• Recognise different examples of forces.

• List the main types of force.

• Represent forces using arrows.

Key Vocab:

weight

lift

Engine thrust

Air resistance

lift

weight

WeightUpthrustLiftFrictionAir resistancethrust

Lesson 7: Weight, Mass and gravity

In and On: What is mass? What is weight? Are they the same thing? Explain

Learning outcomes:• Describe gravity as a non-contact force.• Explore the concepts of gravitational field and weight.• Explain how weight is related to mass.

Mass is: _________________________________________________

________________________________________________________

Weight is: _______________________________________________

________________________________________________________

Gravity is: _______________________________________________

________________________________________________________

Weight = ______ x ______ (weight measured in ___)Mass = ________ / _____ (mass measured in ____)Gravity = ______ / _____ (gravity measured in ______)

An astronaut has a mass of 80 kg. When will he weigh more? Earth – g = 10N/kg Moon – g = 1.5N/kg

The gravitational field strength on earth is around 10 N/kg. What is your weight if your mass is 45 kg?

A measure of how much matter or particles an object has.

A measure of how strongly gravity pulls on an object’s matter.

A field that causes an attraction force between object because all objects have mass

mass gravity

mass

gravityweightweight

Nkg

N/kg

Weight = mass x gravity 45 x 10 = 450 N

Weight = 80 x 10= 800 N

Weight = 80 x 1.5= 120 N

My mass is __________. On earth my weight is _______. (g = 10N/kg)

On Mars, gravity is 4 N/kg.

If I lived on Mars my MASS would be ………………… kg.

If I lived on Mars my WEIGHT would be …………………………… N.

Planet My mass Gravity My weight

Mercury kg 4 N/kg N

Venus kg 9 N/kg N

Earth kg 10 N/kg N

Mars kg 4 N/kg N

Jupiter kg 25 N/kg N

Saturn kg 10 N/kg N

Uranus kg 9 N/kg N

Neptune kg 11 N/kg N

Complete the table:Does your mass change?

Does your weight change?

Where do you weigh the most? Least?

Decide which of the following statements are true and which are false.

Rewrite the false ones to change them into true statements.

a) The weight of an object is always the same.

b) Weight is a force, so it is measured in newtons.

c) The mass of an object depends on the strength of the gravitational field.

d) Gravitational field strength gets weaker the further you are from the object causing it.

e) The Earth’s gravitational field reaches to the edge of the atmosphere but no further.

__________________________________________________________________________________________________________________Use your knowledge about matter, gravitational field strength and forces to explain why, for a particular object, mass does not vary but weight does.

__________________________________________________________________________________________________________________

Imagine a mouse and an elephant falling towards the Earth. Calculate the force due to gravity and the acceleration due to gravity for the mouse with a mass of 100 g and for the elephant with a mass of 5000 kg. Assume that air resistance has no effect. Where it helps, draw diagrams to explain your answer.

45 kg 450 N

45

45 x 4 = 180 N

45

45454545454545

180405450180

450405405

1125

no

yes

Most = JupiterLeast = Mercury or Mars

falseThe mass of an object is always the same.

truefalse

The weight of an object depends on the strength of the gravitational field.

true

Gravity goes to the edge of the Universe. The Earth’s gravity pulls on the Moon and makes the Moon orbit around the Earth.

false

Mass depends on the number of particles in an object. The number of particles does not change when the object is moved. Weight depends on gravity and gravity is not the same everywhere.

MOUSE mass = 100 ÷ 1000 = 0.1 kg weight = 0.1 x 10 = 1 N

ELEPHANT mass = 5000 kg weight = 5000 x 10 = 50,000 N

Plenary: Mini Quiz!! Write true or False

1) Mass is measured in grams and kilograms.

2) Weight is the same as mass.

3) The moon orbits the sun.

4) Gravitational forces change on other planets.

5) Earth orbits the sun every 24 hours.

6) You weigh less on the moon.

7) Your mass changes in space



• Describe gravity as a non-contact force.

• Explore the concepts of gravitational field and weight.

• Explain how weight is related to mass.

Key Vocab:

true

true

true

false

false

false

false

MassWeightNewtonKilogramGravitationalParticlesNkgN/kg

ks3 science forces 1 - rastrick high school€¦ · ks3 science forces 1 name: _____ class: _____...

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