Momentum and Collisions - Mission MC1 Detailed Help

A rightward moving object is slowing down. The direction of its momentum is ____.

Momentum as a Vector:
Momentum is a vector and has a direction. The direction of an object's momentum is in the same direction that the object is moving. Whether slowing down, speeding up or moving with a constant speed, an eastward moving object has an eastward momentum.

Acceleration is often confused with momentum. Both are vectors and both have direction. For acceleration, the direction is dependent upon which way the object is moving and whether it is slowing down or speeding up. So if an object is moving upward and slowing down, its acceleration is downward (opposite the direction of motion whenever slowing down). But don't be fooled! The rule for the direction of momentum is quite different. If an object is moving upward, it's momentum is upward. Whether it is speeding up or slowing down is insignificant.