Which of the following expresses the kinetic energy formula?

• A. F = mv
• B. KE = 1/2 m v^2
• C. V = m g h
• D. W = F d

Answer: (B)

Kinetic energy is the energy that an object has because it is moving. It grows with both how heavy the object is and how fast it’s going, and crucially the speed matters squared. That leads to the standard non-relativistic expression for kinetic energy: KE = 1/2 m v^2, where m is mass and v is speed. Because velocity is squared, doubling the speed increases the energy fourfold, while doubling the mass doubles the energy.

This formula specifically captures motion energy, not other forms. For example, an expression like F = mv would mix up force and momentum, since momentum is p = mv and force relates to changing momentum over time. An expression V = m g h describes gravitational potential energy, not motion energy. And W = F d is the work done by a force over a distance, which relates to energy transfer, not the kinetic energy formula itself.

So the correct expression for kinetic energy is KE = 1/2 m v^2.