Question

Which of the statements are correct

1) the sum of the kinetic energy and potential energy is called the total mechanical energy

2) the sum total of energy in a system is constant

Answer 1

1 statement is correct but 2 statement is wrong.

Mechanical energy is the sum of the potential and kinetic energies in a system. The principle of the conservation of mechanical energy states that the total mechanical energy in a system (i.e., the sum of the potential plus kinetic energies) remains constant as long as the only forces acting are conservative forces.