Science, asked by manjulatarout41098, 10 months ago

what is conservation of energy ?define properly with derive it.​

Answers

Answered by Anonymous
3

Answer:

In physics and chemistry, the law ofconservation of energy states that the totalenergy of an isolated system remains constant; it is said to be conserved over time. This law means that energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another.

Answered by zakirhussain786
1

Answer:

law of conservation of energy states that energy can neither be created nor destroyed but can be transformed from one form to another.

Let us now prove that the above law holds good in the case of a freely falling body.

Let a body of mass 'm' placed at a height 'h' above the ground, start falling down from rest.

In this case we have to show that the total energy (potential energy + kinetic energy) of the

body A, B and C remains constant i.e, potential energy is completely transformed into kinetic energy.

conservation of energy Body of mass m placed at a height

At A, Potential energy = mgh

Kinetic energy = 0 [the velocity is zero as theobject is initially at rest]

Total energy at A = Potential energy + Kinetic

energy.

Total energy at A = mgh ..1

At B Potential energy = mgh = mg(h - x) [Height from the ground is (h-x)] Potential energy = mgh - mgx Kinetic energy = ½ mv².The body covers the distance x with a velocity v.

We make use of the third equation of motion to obtain velocity of the body.

Here, u=0, a=g and s=x

Kinetic energy = mgx

Total energy at B = Potential energy + Kinetic

energy

Total energy at B = mgh..2

At C, Potential energy = m x g x 0

Potential energy = 0

Kinetic energy = ½ mv²

The freely falling body has covered the distance

h.

Here, u=0, a=g and s=h

Kinetic energy = 1/2 mv²

= Kinetic energy = mgh

Total energy at C = Potential energy +

energy

Total energy at C = mgh ..3

It is clear from equations 1, 2 and 3 that the total energy of the body remains constant at every point. Thus, we conclude that law of conservation of energy holds good in the case of a freely falling body.

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