Question

an object falls off a cliff. what remains constant?

Explanation:

Step1: Recall energy - conservation principle

In the absence of non - conservative forces (such as air resistance being neglected here), the mechanical energy of the object is conserved. Mechanical energy \(E = KE+PE\), where \(KE=\frac{1}{2}mv^{2}\) (kinetic energy) and \(PE = mgh\) (potential energy). As the object falls, its potential energy is converted into kinetic energy, but the sum of kinetic and potential energy remains the same.

Answer:

The mechanical energy of the object remains constant.