Summarizing Kinetic Energy and the Work-Energy Theorem

Summary

• The net work \({W}_{\text{net}}\) is the work done by the net force acting on an object.
• Work done on an object transfers energy to the object.
• The translational kinetic energy of an object of mass \(m\) moving at speed \(v\) is \(\text{KE}=\frac{1}{2}{\text{mv}}^{2}\).
• The work-energy theorem states that the net work \({W}_{\text{net}}\) on a system changes its kinetic energy, \({W}_{\text{net}}=\frac{1}{2}{\text{mv}}^{2}-\frac{1}{2}{m{v}_{0}}^{2}\).

Glossary

net work

work done by the net force, or vector sum of all the forces, acting on an object

work-energy theorem

the result, based on Newton’s laws, that the net work done on an object is equal to its change in kinetic energy

kinetic energy

the energy an object has by reason of its motion, equal to \(\frac{1}{2}{\text{mv}}^{2}\) for the translational (i.e., non-rotational) motion of an object of mass \(m\) moving at speed \(v\)