describing motion 2012

Describing MotionIntroduction to Kinematics

2012-13

Stephen Taylor & Paul WagenaarCanadian Academy, Kobe

Canadian Academy inspires students to inquire, reflect and choose to compassionately impact the world throughout their lives.

How do you know that something is moving?

Whee! By Todd Klassy, via the Physics Classroom Gallery http://www.flickr.com/photos/physicsclassroom/galleries/72157625424161192/

http://www.flickr.com/photos/latitudes/


http://www.flickr.com/photos/physicsclassroom/galleries/72157625424161192/






How do you know that something is moving?

Motion is change. Mechanics is the Science of Motion.Kinematics is the science of describing motion using graphs, words, diagrams and calculations.

Our unit question:“How can we describe change?”

Significant concept: Change can be communicated using descriptions, graphical representations and quantities.










How can we describe change?


• Distinguish between scalars and vectors.• Distinguish between distance and displacement.• Describe displacement of an object using components (coordinates), magnitude and direction

and directed line segment vector diagrams.• Describe motion of an object in a given direction based on positive and negative displacement.• Calculate distance and displacement from a map.• Plot distance and displacement graphs from raw data or a strobe diagram• Distinguish between instantaneous and average speed/velocity. • Calculate average speed and velocity from a displacement-time graph or set of recorded data.• Analyze a displacement-time graph to show various types of motion (constant, resting,

direction etc).• Analyze a velocity-time graph to describe changes in motion.• Draw and analyze vector diagrams to show velocity (magnitude and direction)• Convert velocity in km/h to m/s and vice-versa.• Calculate distance (displacement), speed (velocity) or time from a word equation giving other

key information.• Define acceleration.• Calculate acceleration from a set of data.• Deduce a formula to determine instantaneous velocity from a given acceleration.• Explain why objects moving at constant speed can experience acceleration, but not those

moving at constant velocity.









Where are we going?

http://www.slideshare.net/gurustip/qr-orienteering-rokko-island

Complete the QR Code orienteering course to learn about describing motion using:• scalars and vectors• components• magnitude and direction• directed line segments











North

South

EastWest

“North of West”

“East of North”

“ South of East”

“ West of South”

“West of North”

“South of West”

“ East of South”

“ North of East”

Where are we going?

North

South

EastWest

“North of West”

“East of North”

“ South of East”

“ West of South”

“West of North”

“South of West”

“ East of South”

“ North of East”

origin

A BC

D

E

F

G

m.socrative.com/student/Room: N304

Three ways of describing displacement

N

E

Components (coordinates or directional descriptors)- e.g. 3mE, 2mN of origin

Magnitude and Direction

- described, e.g. 2.1m 35oN of West

Vectors (directed line segments) - direction and magnitude are important

North

West

3m2m

Scalars vs Vectors Non-directional quantities

DistanceHow far an object travels along a path

SpeedRate of change of the position of an

object, e.g. 20m/s

Quantities with direction

DisplacementPosition of an object in reference to an origin or previous position

VelocityRate of change of the position of an object in a given direction, e.g. 20m/s East

“per unit time”

v= Δd Δt

Average speed or velocity

Change in distance or displacement

Change in time

More scalars:Time

EnergyMass

Volume

More vectors:AccelerationForceElectric field

Where are we going?Formative assessed task for Criterion E: Processing Data. As a group, present your completed course map, calculations and summary of what you learned on a poster. Comment on the reliability of the data.

Individually design a new, 4-point course using all methods of describing displacement. Location 4 may not be back at the origin. Calculate total distance and displacement for the course.

Where are we going?Individually design a new,4-point course.

Draw vector diagrams on the map.

Two moves must be described using components.

Two moves must be described using magnitude and direction.

Calculate total distance along vector diagrams.

Calculate total displacement from the origin.This includes direction.

Show all working.

1

2

3

4

http://www.youtube.com/watch?v=gWnfqSxp-Dc

Unstoppable A runaway train with no brakes and a load of really dangerous chemicals is heading right for your town.

How long have you got? What questions do you need to ask?

Train cartoon from: http://www.mytrucks.co.uk/how_to_draw_a_steam_train.htm http://en.wikipedia.org/wiki/CSX_8888_incident








http://www.mytrucks.co.uk/how_to_draw_a_steam_train.htm




http://en.wikipedia.org/wiki/CSX_8888_incident





Unstoppable A runaway train with no brakes and a load of really dangerous chemicals is heading right for your town.

How long have you got?

Train cartoon from: http://www.mytrucks.co.uk/how_to_draw_a_steam_train.htm

A B

113.4km

v td

210m in 10s


x
















How do I convert between m/s and km/h?

kmh =1 m

s = ms

How do I convert between m/s and km/h?

kmh =1 m

s = ms

100060 x 60

10003600.

To convert from m/s to km/h, multiply by 3.6.

To convert from km/s to m/s, divide by 3.6.

1 m/s = 3.6km/h

km/hm/sx 3.6

÷ 3.6

Calculating Speed Practice

Cyclist clipart from: http://www.freeclipartnow.com/d/36116-1/cycling-fast-icon.jpg

1. Three cyclists are in a 20km road race. A has an average speed of 30kmh-1, B is 25kmh-1 and C 22kmh-1. The race begins at 12:00.

a. What time does rider A complete the course?

b. Where are riders B and C when A has finished?

12:00

0 20km10km

ABC

v td

http://www.freeclipartnow.com/d/36116-1/cycling-fast-icon.jpg

http://www.freeclipartnow.com/d/36116-1/cycling-fast-icon.jpg

Calculating Speed Practice2. The speed limit is 40kmh-1. A car drives out of the car park and covers 10m in just 3s. Calculate:

a. The speed of the car in kmh-1.

b. The car comes to a stretch of road which is 25m long. What is the minimum amount of time the car should to take to be under the speed limit?

Car clipart from: http://www.freeclipartnow.com/transportation/cars/green-sports-car.jpg.html

v td

http://www.freeclipartnow.com/transportation/cars/green-sports-car.jpg.html

http://www.freeclipartnow.com/transportation/cars/green-sports-car.jpg.html

This is how far we’ve got.

Splish Splash MrT and Mr Condon go swimming in the 25m RICL pool. Mr C is way faster than MrT.

Free swimmer clipart from: http://www.clker.com/clipart-swimming1.html

How long does it take MrC to lap MrT?How would you work it out?

25m in 18s25m in 20s

MrCMrT

http://www.clker.com/clipart-swimming1.html

Are drivers speeding outside school?

http://www.youtube.com/watch?v=Qm8yyl9ROEM

1 mile = 1.61km

The speed limit is 40km/h.Convert this to m/s.

What are some of the One World issues related to speeding drivers?

In what ways could science be used to catch or prevent speeding drivers?




Aim: Test a quick method using cones and timers to determine whether a car is speeding outside the school or not. The speed limit is 40km/h. • Choose one of the methods on the following slides. • Record as many cars as you can in 15 minutes. • Show working of your calculations.• Consider uncertainties and errors in your results.

v= Δd Δt

20m

Car Distance (m) ±0.1m Time (s) ± ____ s Speed m/s ± ___ Speed km/h ± ___

1 20

2 20

3 20

4 20

5 20

Measure the time taken for cars to cover 20m. Record all cars passing school over a 15 minute period.

Calculate each recording as m/s.

Determine how many cars are breaking the speed limit of 40km/h. Show your working in the conversion from m/s to km/h.

Calculate the minimum time a car must take to pass between the cones whilst remaining within the speed limit.

Evaluate the method, noting limitations and possible improvements.


v= Δd Δt

20m


v= Δd Δt

Free app: http://itunes.apple.com/us/app/simple-radar-gun/id442734303?mt=8

20m

Measure the speed of all the cars that pass by the school in a 15-minute period. Determine how many cars are breaking the speed limit of 40km/h.

Outline the conversion the app uses to get from metres and seconds to km/h.

Calculate each recording as m/s.

Calculate the minimum time a car must take to pass between the cones whilst remaining within the

speed limit.

Evaluate the method, noting limitations and possible improvements.

http://itunes.apple.com/us/app/simple-radar-gun/id442734303?mt=8



The local speed limit is 40kmh-1. If we adopt the method of putting markers at set distances along each road, can you rearrange the equation so that local people can determine whether or not a car is speeding – just by counting?

t.v = d

t = d v

v= Δd Δt

Sampled distance (you decide)This example: 50m

50m

40kmh-1

50m

40 x 10003600( )

50m

11.1ms-1 4.5s= = ==


Are drivers speeding outside school?Evaluate the method: • Are data reliable? (enough repeats, acceptable uncertainty/error)• Are data valid? (did we measure what we set out to measure?)• What are the limitations of the method, how might they have impacted the

results and how could they be improved?

Representing motion graphically

Sketch two curves for Michael Johnson: • Distance/time• Displacement/time http://www.youtube.com/watch?v=zbqy1Rpjgmw#t=2m18s

Distinguish between distance and displacement.

0 4515 30

400

200

100

300

time (seconds)

d (m

etre

s)

http://www.youtube.com/watch?v=zbqy1Rpjgmw%23t=2m18s





mailto:http://www.youtube.com/watch?v=zbqy1Rpjgmw%23t=2m12s


Walk This Way Using LoggerPro to generate distance/time graphs.

Challenge 1: • Open the experiment “01b Graph Matching.cmbl”• Give everyone a chance to move themselves to follow the line as closely as

possible. Make sure the motion sensor is aimed at the body the whole time. • Save some good examples and share them with the group.

What does the line show?

resting

Fast constant motion

Slow constant motion

away from the sensor

towards the sensor


Challenge 1: • Open the experiment “01b Graph Matching.cmbl”• Give everyone a chance to move themselves to follow the line as closely as

possible. Make sure the motion sensor is aimed at the body the whole time. • Save some good examples and share them with the group.

What does the line show?

resting

resting

resting

Fast constant motion

Slow constant motion

away from the sensor

towards the sensor


Challenge 2: • Open the experiment “01a Graph Matching.cmbl”• Produce your own – differently-shaped - 10-second motion that includes all of the

following characteristics:• Slow constant motion, fast constant motion and resting (constant zero motion)• Motion towards and away from the sensor• Acceleration• Changes in motion

Save your graph and share it with the group.

Label the parts of the graph and add it to your word doc for submission to Turnitin.

Speed or Velocity?Speed is the rate of change of position of an object.

Over time How fast is it moving?Speed is a scalar quantity. e.g. m/s

(metres per second)

Velocity is the rate of change of position of an object – with direction.

How fast is it moving in that direction?Velocity is a vector quantity.

e.g. m/s East (metres per second to the East)

Warm-up questions1. Your average speed on a 64m journey is 80kmh-1. How long does it take?

2. A duck is on a pond. It starts 8m from the North edge and and swims for 10 seconds. It finishes 2m North of the edge.

a. What was its velocity?

b. Draw a vector diagram to show its displacement.

Calculating Speedv= Δd

ΔtAt what speed did the object move away from the sensor?

v= Δd Δt



Δd

Δt v=



2.5m – 1m = 1.5m

Δd

Δt 3s – 1s = 2s v= 1.5m 2s



2.5m – 1m = 1.5m

Δd

Δt 3s – 1s = 2s v= 1.5m 2s = 0.75m/s



2.5m – 1m = 1.5m

Δd

Δt 3s – 1s = 2s v= 1.5m 2s = 0.75m/s

(2d.p.)


ΔtAt what speed did the object move toward the sensor?

v= Δt Δd



Δd

Δt

v= Δt Δd



2.5m – 1.75m = 0.75m Δd

Δt 7.5s – 6s = 1.5s

v= 0.75m

1.5s = 0.5m/s

Remember: speed is a scalar, not a vector, so direction is not important (don’t use negatives)

Instantaneous Speedv= Δd

ΔtIs the speed of an object at any given moment in time.

X

X

XX

X

no line

Instantaneous Speedv= Δd

ΔtIs the speed of an object at any given moment in time.

v = 0.5m/s

v = 0.75m/s

v = 0.00m/s

v = 0.00m/s

v = 0.00m/s

X

X

XX

X

Average Speedv= Δd

ΔtIs the mean speed of an object over the whole journey.

v= 1.5m + 0.75m 10s

= 0.225m/s

Δd Δd +

Δt = 10 seconds

“mean”

Every movement adds to the total distance traveled

Calculating Velocityv= Δd

ΔtAt what velocity did the object move away from the sensor?

v= Δd Δt



Δd

Δt v=



2.5m – 1m = 1.5m

Δd

Δt 3s – 1s = 2s v= 1.5m 2s



2.5m – 1m = 1.5m

Δd

Δt 3s – 1s = 2s v= 1.5m 2s = 0.75m/s

(away from sensor)

When the person moves away from the sensor, distance and displacement are the same.



1.75m – 2.5m= -0.75m

Δd

Δt

v= 0.75m 1.5s = -0.5ms-1

(toward sensor)

When the person moves toward the sensor, displacement is lost.

Positives and Negatives in VelocityVelocity is direction-dependent. It can have positive and negative values.We can assign any one direction as being the positive.

In the ball-throw examples, the data-logger has assigned movement away from the sensor (gaining displacement) as being the positive. Therefore movement towards the sensor is negative velocity.

Identify which motions show positive, negative and zero velocity.

NNorth is positive. East is positive. South is positive.





+ve

+ve

-ve

-ve

zero





+ve

+ve

-ve

-ve

zero

-ve

-ve

+ve

+ve

+ve





+ve

+ve

-ve

-ve

zero

-ve

-ve

+ve

+ve

+ve

zero

-ve

-ve

+ve

+ve

Instantaneous Velocityv= Δd

ΔtIs the velocity of an object at any given moment in time.

X

XX

X



v = 0.75m/s

v = 0.00m/s

v = 0.00m/sX

XX

X



v = -0.5m/s

v = 0.75m/s

v = 0.00m/s

v = 0.00m/sX

XX

XVelocity is a vector. It is direction-specific. This point moving closer to the origin can be negative.

Average Velocityv= Δd

ΔtIs the mean velocity of an object over the whole journey.

v=

“mean”

Average Velocityv= Δd

ΔtIs the mean velocity of an object over the whole journey.

v= 1.75m – 1.00m

10s = 0.075m/s

Δd

Δt = 10 seconds

“mean”

(away from sensor)

Comparing Speed and Velocityv= Δd

Δt

v= 0.075m/s (away from sensor)

v= 0.225m/sMean speed

Mean velocity

Mean speed is non-directional. ∆d = all distances Mean velocity is directional. ∆d = total displacement

Calculating Speed & Velocityv= Δd

ΔtCalculate the following in your write-ups.

Challenge A: a) Your speed of movement away from the sensor b) Your average velocity over the 10-second run

Challenge B: c) Your instantaneous velocity at any single point of constant motion d) b) Your average velocity over the 10-second run

Ball Challenge (coming up): a) Maximum velocity of the ball when falling b) Average velocity of the ball


Ball Challenge: • Open the experiment “02 Ball.cmbl”

• Position the motion sensor on the floor or table, facing up. • Hold the volleyball about 3m above the sensor• Have someone ready to catch the ball before it hits the sensor. • Start the sensor, drop and catch the ball. Do this a few times.

• Save and label the two graphs: distance/time and velocity/time. • Use these in your write-up to explain what is meant by velocity.

Explain this!Distance from sensor (m)

Velocity (ms-1)

Explain this!Distance from sensor (m)

Velocity (ms-1)

Speeding up Slowing

Changing direction

Speeding up(falling) Caught

Changing direction

Resting

Resting

Let go

Going upwards Falling

Speeding up

Slowing Speeding up

Caught

Walk This Way Submitting your work

Lab report• Assessed for Criterion E: Processing Data

• Complete all the work in the class period to avoid homework. • Self-assess the rubric using a highlighter tool before submission. • Submit to Turnitin.com

Pay attention to the task-specific clarifications to make sure you achieve a good grade

Calculating values on a curve

Distance from sensor (m)

Time (s)

If we are calculating values of constant motion, life is easy. There is a straight line and we can draw a simple distance-time triangle to calculate speed or velocity.

XWhat about here?



Time (s)


XWhat about here?

A triangle is not representative of the curve!



Time (s)


X

If we draw a tangent to the curve at the point of interest we can use the gradient of the line to calculate the speed or velocity of the object – at that moment in time.



Time (s)


X

Now the triangle fits the point.

If we draw a tangent to the curve at the point of interest we can use the gradient of the line to calculate the speed or velocity of the object – at that moment in time.



Time (s)


X

If we draw a tangent to the curve at the point of interest we can use the line to calculate the speed or velocity of the object – at that moment in time.

Now the triangle fits the point.

v= Δd Δt

(0.6m – 0.25m)

(0.4s)= = 0.875m/s

This is a displacement-time graph for the One-Direction tour bus. • Did they really go in one direction? How do you know? • Calculate their velocity at 2s• Calculate their average velocity (over the whole journey)

Speed and VelocityA ball is thrown up in the air and caught. Determine:

a. The instantaneous velocity of the ball at points A and Bb. The average velocity of the ball.

v= Δd Δt

Dis

plac

emen

t (m

)

Time (s) 1 0.50

1

2

A

B

Velocity and VectorsVelocity is a vector – it has direction. We can use velocity vector diagrams to describe motion.

The lengths of the arrows are magnitude – a longer arrow means greater velocity and are to scale. The dots represent the object at consistent points in time. The direction of the arrow is important.

v= Δd Δt

Describe the motion in these velocity vector diagrams:

+

origin

origin

origin

+

origin +

Positive velocity, increasing velocity.

Velocity and Vectors v= Δd Δt

Describe the motion in these velocity vector diagrams:

+

origin

origin

origin

+

origin +

Object moves quickly away from origin, slows, turns and speeds up on

return to origin.

Positive velocity, increasing velocity.

Negative velocity, increasing velocity.

Positive velocity, decreasing velocity.

Velocity is a vector – it has direction. We can use velocity vector diagrams to describe motion.

The lengths of the arrows are magnitude – a longer arrow means greater velocity and are to scale. The dots represent the object at consistent points in time. The direction of the arrow is important.

Posi

tive

velo

city

, dec

reas

ing

velo

city

. Negative velocity, increasing velocity.

Velocity and Vectors

Draw velocity vectors for each position of the angry bird to show its relative instantaneous velocity. Use the first vector as a guide. The flight takes 2.3s. Calculate:• vertical displacement of the bird. • average velocity (up) of the bird. • average velocity (right) of the bird.• average overall velocity (include direction and magnitude)

55cm

1.6m

7.5 m

The birds are angry that the pigs destroyed their nests – but luckily they have spotted a new nesting site. However, short-winged and poorly adapted to flight, they need to use a slingshot to get there.

Velocity and VectorsDraw velocity vectors for each position of the angry bird to show its relative instantaneous velocity. Use the first vector as a guide.

Velocity and VectorsDraw velocity vectors for each position of the angry bird to show its relative instantaneous velocity. Use the first vector as a guide.

Remember that velocity vectors represent velocity – not distance. So it doesn’t matter if there is an object in the way

– the velocity is the same until the moment of impact.

Velocity and VectorsDraw velocity vector diagrams for each of these karts.

10km/h 16km/h 8km/h 20km/h

Use the known vector as the scale.

Velocity and VectorsDraw velocity vector diagrams for each of these karts.

Use the known vector as the scale.

10km/h 16km/h 8km/h 20km/h

Velocity and VectorsA rugby ball is displaced according to the vector below, for 0.6 seconds. Determine the velocity of the ball.

2m

30o

Velocity and VectorsA rugby ball is displaced according to the vector below, for 0.6 seconds. Determine the velocity of the ball.

2m

30o

10m

v= Δd Δt = 10

0.6 = 16.7m/s(30o up and forwards)

What do you feel when…… playing on a swing? (You know you’re not too cool for that)

… taking off on an aeroplane?

… driving at a constant 85km/h on the freeway?

… experiencing turbulence on an aeroplane?

… cruising at high altitude on an aeroplane?

… slowing your bike to stop for a cat?

Acceleration is the rate of change in velocity of an object

Which cars are experiencing acceleration? Find out here: http://www.physicsclassroom.com/mmedia/kinema/acceln.cfm

origin 30 60 90 120 150 180

Sketch distance – time graphs for each car (on the same axes)

What do the shapes of the lines tell us about the cars’ motion?

Dist

ance

Time

http://www.physicsclassroom.com/mmedia/kinema/acceln.cfm

http://www.physicsclassroom.com/mmedia/kinema/acceln.cfm

Acceleration is the rate of change in velocity of an objectAcceleration can be positive (‘speeding up’) or negative (‘slowing down’).

An object at rest has zero velocity and therefore zero acceleration.

An object at constant speed in one direction is not changing its velocity and therefore has zero acceleration.

Velocity is a vector – the rate of change of displacement of an object. Displacement and velocity are direction-dependent.

Therefore, a change in direction is also a change in acceleration.

a= Δv Δt

Acceleration

a= Δv Δt

acceleration

Change in velocity

Change in time= Initial velocity – final velocity (m/s)

Time (s)

m/s/s“Metres per second per second”

Accelerationa = 3m/s/s

Time (s) Velocity (m/s)

0 0

1

2

3

4

formula

00 1 2 3 4

Velo

city

(ms-1

)

Time (s)



0 0

1 3

2 6

3 9

4 12

formula

12

9

3

0

6

0 1 2 3 4

Velo

city

(m/s

)

Time (s)



0 0

1 3

2 6

3 9

4 12

formula v = 3t

12

9

3

0

6

0 1 2 3 4Time (s)

The velocity – time graph is linear as it is constant acceleration.This means it is increasing its velocity by the same amount each time. What would the distance – time graph look like?

Velo

city

(m/s

)



0 0

1 3

2 6

3 9

4 12

formula v = 3t

12

9

3

0

6

0 1 2 3 4

Velo

city

(ms-1

)

Time (s)

A car accelerates at a constant rate of 3m/s/s.Calculate its instantaneous velocity at 7.5s: a. in m/s

b. in km/h

Calculate the time taken to reach its maximum velocity of 216km/h.

Accelerationa = 3m/s


Displace-ment (m)

0

1

2

3

4

formula

12

9

3

0

6

0 1 2 3 4

Velo

city

(m/s

)

Time (s)

Determine the velocity and displacement of the object each second. Plot the results on the graph. Compare the shapes of the two graphs.

3

9

18

30

Displacem

ent (m)

Accelerationa = 3m/s


Displace-ment (m)

0 0

1 3

2 6

3 9

4 12

formula v = 3t

12

9

3

0

6

0 1 2 3 4

Velo

city

(m/s

)

Time (s)

The displacement – time graph is curved as it is constant acceleration – the rate of change of displacement increases. This means it is increasing its velocity by the same amount each time.

3

9

18

30

Displacem

ent (m)



Displace-ment (m)

0 0 0

1 3 3

2 6 9

3 9 18

4 12 30

formula v = 3t

12

9

3

0

6

0 1 2 3 4

Velo

city

(m/s

)

Time (s)The displacement – time graph is curved as it is constant acceleration – the rate of change of displacement increases. This means it is increasing its velocity by the same amount each time.

3

9

18

30

Displacem

ent (m)

Acceleration

00 1 2 3 4

Velo

city

(ms-1

)

Time (s)

a = -2ms-2

Time (s) Velocity (ms-1)

0 10

1

2

3

4

formula

Acceleration

00 1 2 3 4

Velo

city

(ms-1

)

Time (s)

a = -2ms-2

Time (s) Velocity (ms-1)

0 10

1 8

2 6

3 4

4 2

formula

Acceleration

00 1 2 3 4

Time (s)

a = 2kmh-1s-1

Time (s) Velocity (kmh-1)

0 10

1

2

3

4

formula

Acceleration

00 1 2 3 4

Time (s)

a = 2kmh-1s-1

Time (s) Velocity (kmh-1)

0 10

1

2

3

4

formula

Velo

city

(km

h-1)

10

18

How is it possible for an object moving at constant speed to

experience acceleration, but not an object moving at constant velocity?

How is it possible for an object moving at constant speed to experience acceleration, but not an object moving at

constant velocity?Image: Moon from northern hemisphere: http://en.wikipedia.org/wiki/Moon

http://en.wikipedia.org/wiki/Moon



Who’s faster?

Bolt vs Gump, from http://www.ew.com/ew/gallery/0,,20220853_20499114,00.html#20499196

http://www.youtube.com/watch?v=3nbjhpcZ9_g Usain Bolt’s 100m world record:

100m 0m

Gump

Bolt

Strobe diagram: each dot is the position of the runner after one second.

http://www.youtube.com/watch?v=3nbjhpcZ9_g



Graphing Motion


100m 0m

Gump

Bolt

Sketch a distance/ time graph for Gump and Bolt.


Graphing Motion


100m 0m

Gump

Bolt

Plot a distance/ time graph for Gump and Bolt.What other analysis can be carried out with these data? Discuss and do it!


Gump vs. Bolt

Bolt vs Gump, from http://www.ew.com/ew/gallery/0,,20220853_20499114,00.html

#20499196

Blog post: Describing Motion Review

Use the Gump vs Bolt data to write a blog post. It will act as a review of the content of the unit (check the assessment statements on your review sheet), as well as an informative article for others.

You can write it as: • A local reporter for the Greenbow, Alabama paper• A sports reporter writing about Bolt and the Olympics• A straight-up scientific explainer for HS studentsLook at the criteria and the assessment statements. As a small group, make and share a list of task-specific clarifications. Check, draft, write, cite.

It will be assessed for Criterion B: Communication in Science:

Infographic from: http://www.telegraph.co.uk/sport/olympics/olympic_infographics_and_data/9453618/London-2012-Olympics-battle-of-the-sprint-kings-Usain-Bolt-and-Yohan-Blake.html

Bolt vs Blake: What do the data tell us?

http://www.telegraph.co.uk/sport/olympics/olympic_infographics_and_data/9453618/London-2012-Olympics-battle-of-the-sprint-kings-Usain-Bolt-and-Yohan-Blake.html








Unit Test: Describing MotionCriterion C: Knowledge & Understanding in Science

Unit Test: Describing MotionCriterion C: Knowledge & Understanding in Science

Reflection on the back of the test: 1. What have you learned during this ‘Motion’ unit

that you didn’t know before?

2. What have you learned about how you learn?

3. Do you think your performance in the test is a good reflection of your learning? Why?

4. Do you think the test was fair and allowed you to demonstrate what you had learned? How would you improve it?

5. How will you build on this for next time?

If you’re done:• Rokko Liner Plans!

Rokko Liner Project

Spare Slides

time

velo

city

AB

CD

E F

G

dist

ance

time

A

BC

D

E

What are the coordinates of these objects?

origin

2mE, 1mN

Coordinates can be used to describe an objects position or displacement.

Pick a mystery object. Describe the displacement to three other objects. Can another group deduce the objects?

Example:

From (mystery object)

It is:• 1mE, 1mS to the

______________________ • 4mS to the

______________________• 2mS, 4mE to the

______________________


Example:

From (mystery object)

It is:• 1mE, 1mS to the Big Squirrel • 4mS to the Enthusiastic Runner• 2mS, 4mE to the Tiny Cyclist


Example:

From (Giant Acorn)

It is:• 1mE, 1mS to the Big Squirrel • 4mS to the Enthusiastic Runner• 2mS, 4mE to the Tiny Cyclist

The components (coordinates) of displacement tell us where the object has moved to overall, but they do not necessarily tell us the path it has taken.

Which objects are:• 2.1m away from the origin at 14oN of East?• 5m away from the origin at 30oN of East?

Magnitude and Direction tell us the displacement in terms of the most direct path.

5m le

ngth

E

N

30o North of East

origin

Magnitude and Direction can also be represented by directed line segments (vector diagrams).

E

N

1m

The direction (angle relative to the orientation) and magnitude (length of the vector) are important.

Which objects lie closest to these vectors?(directed line segments – hint, start at origin, length is important)

N

E

N

E

N

E

A

B

C

Describing displacement

NComponents (coordinates or directional descriptors)- e.g. 3mE, 2mN of origin

Magnitude and Direction- described, e.g. 2.1m 14oN of

origin

Vectors (directed line segments) - direction and magnitude are important

1kmN

$

Ke$ha’s Day Out on Rokko Island

Wake up feeling like P Diddy

1. Wake up in the morning (11am) feeling like P Diddy. 2. Get a pedicure, 5kmE 2.5kmS of home. 3. Then hit the clothes store, 30oNorth of East 5km away. 4. Cruise along, top down, CD’s on. Along this vector (directed line segment) to club.5. Club closes 1am. Walk home.6. Arrive home 4am by most direct route.

1kmN

$



1. Wake up in the morning (11am) feeling like P Diddy. 2. Get a pedicure, 5kmE 2.5kmS of home. 3. Then hit the clothes store, 30oNorth of East 5km away. 4. Cruise along, top down, CD’s on. Along this vector (directed line segment) to club.5. Club closes 1am. Walk home.6. Arrive home 4am by most direct route.

Pedicure

Clothes

Club

1kmN

$



1. Calculate:a. Total distance b. Total displacement c. Average speed d. Average

velocity

e. Average speed on the walk home.

2. Describe the displacement of the pedicurist from her house using:

a. directed line segment b. direction and magnitude

Pedicure

Clothes

Club

Sketch a velocity-time graph for this journey.

0.5s

0.2m

Calculate velocity before it hits the fabric.

Thrown up at 12m/sAccelerates down at 10m/s/sHits water at 4s.

What is the velocity as it hits the water?

What is the height of the bridge?

Images adapted from http://www.fanpop.com/spots/one-direction/images/28558025/title & http://goo.gl/zJnql

THE ONE DIRECTION TOUR BUS

http://goo.gl/zJnql

http://goo.gl/zJnql

http://goo.gl/zJnql

http://goo.gl/zJnql

http://goo.gl/zJnql

http://goo.gl/zJnql

http://goo.gl/zJnql

http://goo.gl/zJnql

describing motion 2012

Education

distance displacement

given direction

velocity magnitude

speed velocity

magnitudeand direction

constant velocity

displacement graphs

displacementtime graph