Pam ran down the sidewalk to school with her empty backpack. After school, Pam’s backpack was loaded with books. Which best describes the force required to carry her book bag home?
It took the same amount of force to carry the loaded book bag home.
It took a greater amount of force to carry the loaded book bag home.
It took a lesser amount of force to carry the loaded book bag home.
Sam is building a car to race down a ramp. The car weighs 100 grams. Which could Sam do to increase the speed of the car?
increase the mass of the car
decrease the mass of the car
increase the friction on the ramp
How does friction affect speed?
more friction decreases speed
more friction increases speed
less friction decreases speed
Tamara and Justin are racing on the playground. Tamara runs the distance from the basketball goal to the jungle gym in 45 seconds, while Justin runs the same distance in 52 seconds. Which best describes the movement of the students?
The students ran in different directions.
Both students ran at the same speed.
Tamara ran faster than Justin.
A girl walked for 30 minutes. She noticed that she traveled farther in the first 15 minutes of her walk than in the second 15 minutes. What can she conclude about her walk?
She walked over many hills.
Her average speed was faster during the first half of her walk.
She walked in two different directions.
She was walking at a constant speed.
James and Roy compare the motion of two balls by rolling them across the floor and recording the time it takes them to travel the same distance. Ball X travels the distance in 15 seconds. Ball Y travels the distance in 11 seconds. Which best compares the motion of the two balls?
Ball X travels faster than Ball Y.
Ball Y travels faster than Ball X.
Both balls travel at the same speed.
Both balls travel at a constant speed.
Which best describes the force of gravity?
a pulling force
a pushing force
a change in mass
a change in speed
When is friction needed during the course of motion?
to speed up motion
to slow down motion
to keep motion at the same speed
to keep motion in the same motion
Based on the graph, what can be inferred about the speed of the vehicle?