Question

What SI unit is used to measure mechanical energy

Answer 1

The SI unit of energy is the Joule .

Any kind of energy ... electrical, mechanical, nuclear, solar,
wind etc.  It's easy to change from one form to another ... we
do it every day ... and they all have the same unit.

Answer 2

Mechanical energy is the energy of motion and position, breaking it down, you get kinetic and potential energy. 

The SI unit to measure ENERGY is Joule, (pronounced Jowl). 

1 joule = 1 Newton-meter

Answer: Joules