Question

The conservation principle of mechanical energy requires that

• A. The acceleration should be zero
• B. There should be no external forces
• C. The motion should be restricted to the gravitational force
• D. The force should be conservative

Answer 1

Answer: (B)

There should be no external forces

$\text{Explanation:-}$

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.

$\text{Hence the correct option is B}$