What makes it difficult to stop an object? Having a lot of mass or velocity

What does the change in an object's momentum depend on? The force that acts on it and the time it takes

A force applied over a long period has a Greater momentum change than one applied over a short period.

If you can increase the time it takes to slow an object to a stop, you will decrease the Force it will experience.

In the absence of an external force, momentum is conserved.

If there is no outside force present, no change in momentum occurs.

Collions can be categorized by a combination of Elastic and Inelastic.

The net momentum before the collision Equals the net momentum after the collision.

When is work done? When a force acts on an object, the object moves in the direction of the force.

Mass is measured in Kilograms (Kg).

Work is measured in Joules.

Force is measured by Newtons.

When do you do work on something? When you force it to move against the influence of an opposing force—often friction or gravity.

Mechanical energy comes in 2 forms: Potential Energy and Kinetic Energy.

The Kinetic Energy of a moving object is equal to the work required to bring its speed to/from rest.

What is necessary to increase the kinetic energy of an object? Work.

Total energy always remains Constant.