Determine the mechanical energy of this object: a 1-kg ball rolls on the ground at 2 m/s.

Mechanical energy is the sum of kinetic and potential energy in an object that is used to do work. In this case, potential energy would be zero. It is only kinetic energy that is present. We calculate as follows:

Kinetic energy = mv^2 / 2

Kinetic energy = 1 (2^2) / 2 = 2 Joules