Forces vs. Motion
What is a force?
A push or pull on an object.
True or False: A balanced force causes acceleration.
False
If you apply more force to an object, what happens to its acceleration?
It increases
State Newton’s 3rd Law.
For every action, there is an equal and opposite reaction
A flat line on a distance–time graph means what?
The object is at rest.
Give two examples of a force.
Gravity and friction.
Another name for Newton’s 1st Law is…
The Law of Inertia.
What is the formula for Newton’s 2nd Law?
Force = Mass × Acceleration (F = m × a).
When air pushes down and back from a rocket’s engines, what happens to the rocket?
It moves upward and forward
A line that curves upward on a distance–time graph means what?
Acceleration (speeding up).
What is motion?
Motion is movement caused by a force
What does inertia mean?
The tendency of an object to resist a change in motion.
The greater the mass, the ________ the acceleration.
Slower (or less)
Give an example of Newton's 3rd Law
When you jump off a small boat and the boat moves backward.
A line that curves downward means what?
Deceleration (slowing down).
How are force and motion related?
Forces cause changes in motion.
Fill in the blank: An object at rest stays at rest, and an object in motion stays in motion unless acted on by an ____________ force.
Unbalanced.
If a 2 kg object accelerates at 3 m/s², what is the force?
6 N
Two ice skaters (same height, weight, and force) push off each other. They move in opposite directions. Why?
Each exerts an equal and opposite force on the other.
Calculate: 50 m in 10 s. What is the speed?
5 m/s
If two balanced forces act on an object, what happens to its motion?
It doesn’t change (object stays at rest or moves at constant speed).
Give an example of Newton’s 1st Law
You are riding in a car and it suddenly stops. Your body keeps moving forward.
How does Newton’s 2nd Law explain why it’s harder to push a full shopping cart than an empty one?
Because the full cart has more mass, requiring more force for the same acceleration.
Why do astronauts “float” in space even though they still experience gravity?
They are in continuous free fall, so the reaction force equals the pull of gravity.
If an object’s motion graph shows a straight, slanted line upward, what type of motion is that?
Constant speed