# Circular and Satellite Motion - Mission CG2 Detailed Help An object is moving in a circle at a constant speed of 30 m/s. It is known for sure that the object is accelerating because it is ____. Definition of Velocity: The velocity of a moving object is the rate at which the object changes its position. The magnitude (or value) of the velocity is the object's speed. The direction of the velocity vector is the direction that the object is moving.   Definition of Acceleration: The acceleration of an object is the rate at which the object changes its velocity. Accelerating objects are changing their velocity. Velocity is often thought of as an object's speed with a direction. Thus, objects which are accelerating are either speeding up, slowing down or changing directions. Changing the velocity in any one of these three ways would be an example of an accelerated motion. Objects which move in a circle at a constant speed are still accelerating. The acceleration is obviously not due to a changing speed. The acceleration is due to a change in direction.  