motion and speed answers to fusion. motion and speed answers skip 1, 2, and 4—see j#5 motion...

Motion and Speed

Answers to Fusion

Motion and Speed Answers

• Skip 1, 2, and 4—See J#5 Motion Vocabulary• 3 – If an object changes its position, then it is IN

MOTION. It is also changing speed and velocity according to the definitions of both.

– The speed of a car describes how fast it goes; how much distance it has covered in a given amount of time.

5- How would you describe where the question is located on the page?

• Three paragraphs from the start of the page; Four inches from the bottom; Toward the bottom of the page above the straight lines; Under the paragraphs with the caption “With a Reference Point.” …to give just a few. YOU needed at least TWO.

6-Go three blocks south and one block east. 7-Go one block west, one block north, and then two blocks west.

*You were to use directions (N, S, E, W) and blocks! Did you?

8- Come on….it’s a maze. 9-Difference between speed and average speed: Speed measures how fast an object is moving at a specific moment in time (Instantaneous Speed from your other notes). Average speed measures how far an object moves in a given amount of time.

11-

12- Average Speed = Distance ÷ Time

S = 100m / 13.75s

Answer = 7.27 m/s

13—Note…speed is constant-Linear relationship

14—What does the slope say about the speed?

• Steeper lines = faster• Flat lines = not moving! No distance is

covered while time elapses.

15-What happens in the graph?

From 0-1 second, the ATV moved 10 meters. Then, from 1-3 seconds it didn’t move. Time elapsed, but no distance covered. From 3-4 seconds it moved 20 meters and then from 4-5 seconds the speed was constant and it moved another 20 meters. Where was it moving the fastest? From 3-5 seconds.

16-Average Speed of the ATV in graph

Distance = 50 metersTime = 5 seconds

Distance ÷ Time = Speed

50 meters ÷ 5 seconds = 10 meters/second

Distance covered in a given amount of time

Describes how “fast” something goes

Distance covered in a given amount of timeAND direction

18- A reference point is a location to which you compare other locations---TRUE. 19- Distance traveled does not depend on the path you take---FALSE. 20-To calculate speed, you first need to find the mass of an object---FALSE.21-Average speed is a way to describe the speed of an object that may not always be moving at a constant speed.---TRUE. 22- In the graph, the object is moving at a constant speed---TRUE (it is a straight line showing a linear relationship). 23—Amy’s average speed was faster than Ellie’s because Amy went farther (distance) in the same amount of time.

• Compare slopes from A-B, B-C, C-D

Time (Seconds)

Distance (m)

A

B

D

C

C-D is the fastest. I know this b/c the line is the steepest. A-B is the second fastest, again, compare slopes. B-C is not moving. Time elapses, but no distance is covered.

Time (Seconds)

Distance (m)

A

B

D

C

Acceleration

• Velocity (speed) measures a rate of change in position (distance/time).

• Acceleration measures a rate of change in velocity (Velocity/time)….V2-V1/time.

#1

• A car taking a turn at a constant speed is accelerating---TRUE. *Change in velocity due to direction.

• If an object has low acceleration, it isn’t moving very fast---FALSE. *Cruise control in a straight line is one example.

• An accelerating car is always gaining speed---False. *Could just be changing direction for example!

Didn’t do #2 or #4.

• #3-Moving around a center.• #5-Two components of a vector are

magnitude and direction. • #6-Units for acceleration---you should have

underlined: meters per second per second OR in other words, meters per second squared (m/s2)

• #7---velocity is unchanged from B-C!

B---8m/s, t= 1s C ---8m/s, t= 2s

Velocity 2 (8m/s) – Velocity 1 (8m/s) 1 second

0/1 = 0 m/s2 Velocity is unchanged.

• #8—A-B Velocity 2 (8m/s) – Velocity 1 (4m/s) ÷ 1 sec.8-4/1 4 m/s2

Whole trip– (7 m/s-4 m/s) ÷ 3 s 3/3 = 1 m/s2

#9—Increase in velocity (underline) PositiveAcceleration. – Decrease in velocity (underline) Negative

Acceleration.

Centripetal Acceleration#10—What direction is the acceleration in centripetal acceleration, where speed does not change and direction does? --Perpendicular to the direction of motion. In order for an object to execute circular motion - even at a constant speed - the object must be accelerating towards the center of rotation.

How does centripetal acceleration feel in real life?It feels like a force pushing you into the car door when turning. It’s what keeps you in your seat on the rollercoaster, or plastered against the wall in the gravitron.

The centripetal force (created by centripetal acceleration….circular movement creates this) is the force that causes an object to move in a circle, acting towards the center of the circle. In the case of a satellite the centripetal force is gravity, in the case of an object at the end of a rope, the centripetal force is the tension of the rope.