Force & Speed Changes
If three objects change speed by the same amount, what does that mean about the force on them?
They experienced the same amount of force.
If two objects with the same mass change speed equally, what can you say about the forces on them?
The forces are equal.
In a collision, the forces on objects are...
Equal in strength, opposite in direction
Why does crashing affect motion?
Because forces change speed and direction.
What force makes sliding objects slow down?
Friction
True or False: It takes more force to slow something down than to speed it up.
False
When a more massive object changes speed by the same amount as a less massive object, which one experienced the stronger force?
They experienced the same force.
A skateboard and cart collide. If the cart experiences a strong force, what can you say about the skateboard?
The skateboard experiences the same strong force.
True or False: Only one object feels a force in a crash.
False – both objects feel a force.
Why did the wooden block in Question #4 stop moving?
The floor exerted a force opposite the block’s motion.
A ball slows from 10 m/s to 5 m/s. Did it experience a force?
Yes, a force changed its speed (slowing is a speed change).
the speed of an object in a particular direction
velocity
In Question #3, which crash had the stronger force on the skateboard? Why?
Crash 2, because the force on the cart was stronger.
In the asteroid crash (#10), did the asteroid feel a force? Why?
Yes, because the moon/planet changed speed.
A salt shaker slides and stops. Did it “run out of force”?
No, friction slowed it down.
Which ball experienced the strongest force? (Purple 8→12, White 10→14, Green 6→0)
Green, because it changed speed the most.
Finish the sentence: “Objects with more mass require ____ force to change speed.”
More
Why do two boxes slow down after colliding?
They experience equal and opposite forces, causing speed changes.
Even if collisions exert the same force on both objects, what still affects their velocity?
mass
Explain why objects don’t move forever on Earth.
Friction opposes motion and slows objects.
Explain how the amount of speed change relates to the strength of the force.
The greater the speed change, the stronger the force exerted.
If a small ball and a large ball both speed up by 3 m/s, what does this tell you about the forces in the collision?
The forces were equal and opposite on both balls.
Describe force direction in a crash using the phrase “equal and opposite.”
Each object feels a force equal in strength but opposite in direction, changing motion.
The 2 forces in a collision are always in the same direction.
false
What is required to change velocity?
force