force
A push or pull on an object that may or may not cause motion, has a size and direction
velocity
the speed of an object in a particular direction
net force
the combination of all forces acting on an object
newton
the SI unit of force
acceleration
the rate at which velocity changes over time, the rate at which velocity changes over time; an object accelerates if its speed, direction, or both change
Example of acceleration
a boulder rolling down a hill faster
balanced forces
2 or more forces exerted on an object that cancel each other out and don't cause a change in motion
unbalanced forces
2 or more forces exerted on an object that can cause an object to change in motion in a certain direction
gravity
the force of attraction between all masses in the universe
friction
the force that opposes the motion of one surface as it moves across another surface
Decrease friction
adding lubricants
Increase friction
have rougher surfaces; i.e. sandpaper
kinetic friction
friction between moving surfaces
static friction
friction between non-moving surfaces
Newton's 1st Law
an object at rest will stay at rest; an object in motion will stay in motion; unless acted by an outside force
Newton's 1st Law (2nd way of calling it)
Intertia
Newton's 2nd Law
Force is mass times acceleration; an objects acceleration depends on the mass of the object and the size and direction of the force acting upon it
Newton's 3rd Law
Every action force has an opposite, and equal reaction force
fluid friction
friction that occurs as an object moves through a fluid
sliding friction
friction that occurs when one solid surface slides over another
motion
an object's change in position relative to a reference point
speed
the rate at which an object moves
Average speed formula
total distance/total time
Negative acceleration
deceleration