Question

A cook knocks a 95.0 g egg from a kitchen counter top. When the egg is 65.0 cm above the ground, it has a total mechanical energy of 1.12 J. Determine the kinetic energy of the egg.

Answer 1

The total mechanical energy consists of potential and kinetic energies:

$$E_M=E_P+E_K=mgh+mv^2/2,\\\space\\ E_K=E_M-E_P=E_M-mgh,\\ E_K=1.12-0.095\cdot9.8\cdot0.65=0.51\text{ J}.$$