Energy and Momentum

Momentum is the product of mass multiplied by velocity (it is a vector with units‐kg m/s).

Momentum is always conserved, so the total momentum of a system before a crash is the

same as after the crash.

Energy is the ability to do work. Work is the transfer of energy expressed by

the equation W=force* distance. The units of energy and work are Joules.

Power is also related to work, as it is the rate at which work is done (Power= Work÷ time)

Power is expressed in the units of Watts.

There are two categories of energy: Potential Energy and Kinetic Energy.

Between the two, energy is also conserved just like momentum.

Potential Energy is the energy of an object based on its height: more height then more potential energy.

Potential energy= mass*gravity*height.

Kinetic Energy is the energy of an object due to motion: great it's velocity then more kinetic energy.

Kinetic energy= 1/2 mass* velocity^2