Unit 2- Force and Motion Vocabulary- Part I

Frame of Reference  A system of objects that are not moving with respect to each other

Relative Motion  Movement in relation to a frame of reference

Distance  Length between two points

Displacement  The position with respect to the origin; the length and direction from the starting point to the ending point.

Speed  Ratio of the distance traveled to the time the object moves

Average Speed  The total distance traveled divided by the total time traveled

Instantaneous Speed  The rate at which an object is moving at a given moment in time.

Velocity  A description of motion involving both speed and direction.

Acceleration  The change in velocity. It can occur when speed changes, when direction changes or when both speed and direction changes.

Free Fall  The movement of an object toward Earth because of gravity.

Constant Acceleration  A steady change in velocity