Momentum is a property of an object's motion. When a push or a pull (a force) acts on an object and changes its motion, the quantity that gets changed is momentum. Energy is required to change the magnitude (size) of momentum, but not its direction. Specifically, momentum (written as ) is the mass of the object times its velocity (or speed with direction):
Massive objects have more momentum for a given speed, while lighter objects have less momentum. This is why it takes more effort (force) to stop a fully loaded truck than an empty one. Likewise, faster moving objects have more momentum than slower moving objects.
One way to express kinetic energy is in terms of momentum ( ):
Momentum is an important physics concept, to learn more about momentum please see hyperphysics.
The University of Colorado has graciously allowed us to use the following Phet simulation. Explore this simulation to see how momentum is transferred in collisions along with energy:
For further information please see the related pages below: