In terms of work (W) and potential energy (U), how is kinetic energy (K) expressed?

Kinetic energy (K) can be related to work (W) and potential energy (U) through the work-energy principle. This principle states that the work done on an object is equal to the change in its kinetic energy.

In physics, when an object is in motion, it possesses kinetic energy. If work is done on the object, this will either increase or decrease its kinetic energy depending on whether the work is positive or negative. Additionally, potential energy is associated with the position of the object in a gravitational field or other forces.

If we consider a situation where work is done on the object to change its potential energy, it can be understood that the kinetic energy can be expressed in relation to the work done and the potential energy. Thus, the expression K = W - U effectively relates the kinetic energy to the total work performed on the system, accounting for the change in potential energy. This means when work done on the object increases its potential energy, the net energy contributing to kinetic energy is decreased, reflecting the relationship accurately.

This formulation aligns with the understanding that the total energy of a system can be expressed in terms of its kinetic and potential energies, capturing how energy transitions between forms as work is done.