linear+projectile motion
speed
a rate of distance covered per unit of time
a measure of inertia
vector vs. scalar
vector has magnitude and direction scalar has only magnitude
inertia
the resistance of a body to change in its state of motion
free fall
when only gravity acts on an object
force
a push or pull
air resistance
a force caused by air that acts in the opposite direction to an objects moving through the air
normal force
the upward force that balances the weight of an object on a surface
acceleration
a rate if change of an object's velocity
when the net force is 0