Force & Motion
What is a force?
Push or a pull
What does Newton’s First Law say about an object at rest?
It stays at rest unless acted on by a force
What is the formula for force in Newton’s Second Law?
F = M x A
What is Newton’s Third Law?
For every action, there is an equal and opposite reaction.
What happens when forces are unbalanced?
The object speeds up, slows down, or changes direction.
What unit is used to measure force?
Newtons (N).
What is Newton’s First Law also called?
The Law of Inertia.
If you double the force, what happens to the acceleration?
It doubles.
If you push on a wall, what does the wall do?
It pushes back on you with equal force.
What happens to an object when forces are balanced? (2 answers)
It stays still or moves at constant speed.
What two things can a force do to an object?
Change its motion, shape or positioning.
Give an example of Newton’s First Law in sports.
A soccer ball at rest stays still until it's kicked.
If an object has a mass of 2 kg and accelerates at 3 m/s², what is the force?
6 N
When a balloon flies around after letting it go, which force is the action that makes it move?
The air rushing out.
Two people push a box in the same direction. Is this balanced or unbalanced?
Unbalanced
What is the term for how fast something is moving?
Speed.
Why do you lunge forward when a car stops suddenly?
Your body wants to keep moving (inertia).
What happens to acceleration if the mass increases, but force stays the same?
Acceleration decreases.
Why do you move up and forward when you jump off of a diving board into a pool?
The diving board provides an equal and opposite reaction to your push, pushing you up and forward.
A 10 N force to the right and 10 N to the left act on an object. What happens?
The object doesn’t move (balanced forces).
What is velocity?
Speed in a specific direction.
What does inertia mean?
The tendency of an object to resist a change in motion.
Explain Newton’s Second Law in your own words.
The greater the mass, the more force is needed to accelerate it.
Describe how Newton’s Third Law explains how rockets launch into space.
The rocket pushes gas downward; the gas pushes the rocket upward with equal force.
If forces are equal and opposite, what is the net force?
0 N