Question

A pendulum has 100 Joules of total mechanical energy. If 50 Joules are potential energy, how many Joules of kinetic energy must there be?

Answer 1

50J is kinetic energy

Step-by-step explanation:

Mechanical energy, ME, is composed of both kinetic (KE) and potential energies (PE). Kinetic is given by KE = (1/2) mv^2 and potential is given by PE = mg, where m is the mass, v the velocity and g the acceleration due to gravity.

If a pendulum has 100J total energy, we can say that:

KE + ME = 100J

We know that 50J is kinetic energy. The balance, 50J, must tbe due to potential energy.