Forces
What is a force? (simply put)
a push or pull
True or false: Friction is a force
True
What is the definition of inertia?
The tendency of an object to resist change in motion
What letter is used to symbolize momentum?
a lowercase p
Describe what happens when two balanced forces push on each other.
there is no change in motion - the forces cancel each other out.
Define Friction
a force that opposes motion
Define Newton’s 1st Law of Motion.
An object at rest will remain at rest OR an object in motion will remain in motion unless acted on by an outside force.
What are three ways you can write the momentum formula?
p = m·v
m = p/v
v = p/m
Describe what happens when two unbalanced forces push on each other.
There is a change in motion. (This will cause objects to speed up, slow down, or change direction)
What are the four types of friction?
Static, Sliding, Rolling, and Fluid
What is the mathematical formula for Newton's 2nd Law?
Force = Mass x Acceleration
Calculate the momentum of a 2000 kg car moving at a speed of 20 m/s.
p = m x v
p = 2000 x 20 = 40,000 kg m/s
If you push on a wall with a force of 125 N. With how much force does the wall push back on you?
125 N - equal and opposite
You push on a large box and are unable to move it. What force opposes your push?
static friction
Define Newton's 2nd Law of Motion.
The greater the mass of an object, the more force it will take to accelerate the object.
A soccer ball is moving at 4.5 m/s North and has a momentum of 75 kg m/s. What's the mass of the soccer ball?
m = p / v
m = 75 / 4.5 = 16.67 kg
Forces are measured in...
Newtons
If you were to push a large piece of furniture, how could you decrease the frictional force in order to more easily move the large piece of furniture?
Add wheels underneath the furniture to change the static friction into rolling friction. Or add furniture pads under the base to change it into sliding friction.
Define Newton's 3rd Law of Motion.
For every action, there is an equal and opposite reaction.
What is the law of conservation of momentum?
This law states that momentum doesn’t disappear, it just gets transferred.