# Motion

## 8 terms

### motion

an object's change in position relative to a reference point

### displacement

the change in position of an object

### speed

the distance traveled divided by the time interval during which the motion occured. equation(s= distance/time) SI unit (m/s)

### Velocity

the speed of an object in a particular direction. equation(v= displacement/time) SI unit (m/s)

### acceleration

the rate at which velocity changes over time; an object accelerates if its speed, direction, or both change. equation(final velocity- intial velocity/time) SI unit (m/s squared)

### Force

an action exerted on a body in order tochange the body's state of rest or motion; force has magnitude and direction. equation(mass x acceleration)

### static friction

the force that resists the the initiation of sliding motion between two surfaces that are in contact and at rest

### kinetic friction

the force that opposes the movement of two surfaces that are in contact and are sliding over each other