Question

State the law of conservation of energy? Show that when a body falls from a certain height

the total mechanical energy remains conserved.​

Answer 1

According to the law of conservation of energy "the energy of a system remains constant."

In simpler words, it can be written as, 'energy can neither be created nor destroyed; it can only transform from one form to another.'

• If we talk about the freely falling body, the mechanical energy of the system is conserved.
• When a body freely falls, the motion is influenced by the gravitational force.
• When a body falls, it possesses two types of energies. First is potential energy and second one is kinetic energy.
• The total sum of these two energies is called mechanical energy.
• So, mechanical energy (E) is the sum of the kinetic energy (K) and potential energy (U) of the freely falling body.
• Therefore, E=K+U=constant.
• If a body of mass m is placed at a height of h then its potential energy is U=mgh.
• Kinetic energy is the energy possessed by an object or body in motion. If a body of mass m is in motion with speed v, then its kinetic energy is given as K=12mv2.