Speed
Speed: the distance travelled between two points usually measured in m/s (meters per second).
Average speed = distance/time.
Velocity
Velocity: the speed of an object and its direction.
For direction you can use words such as forward, backward, left, right and for motion in a straight line you can use a + or – symbol(+=forward, -=backward).
Velocity is a vector (a vector is something that has mass as well as direction). Acceleration Acceleration: the gradual change in speed.
If something is accelerating it is speeding up.
Average acceleration = change in velocity/time taken.
Acceleration is measured in m/s^2 (meters per second squared).
A negative acceleration is called a retardation or deceleration.
Acceleration is a vector.
A constant acceleration is called a uniform acceleration.