Question

Hii..!!!♡♡♡


=>State law of conservation of energy.

Answer 1

The law of conservation of energy states that energy can neither be created nor be destroyed. 
Eg: A number of electrical and mechanical devices operate solely on the law of conservation of energy.

1.In a microphone, sound energy is converted into electrical energy.
2.In a loudspeaker, electrical energy is converted into sound energy.
3.In a generator, mechanical energy is converted into electrical energy.

Answer 2

$\mathbb{ELLO \ THERE!}$

--------------------------

Question: State law of conservation of energy.

-------------------------

$\mathsf{ANSWER}$

Law of Conservation of Energy

Law of conservation of energy states that Energy cannot be created nor destroyed, it can only be transformed from one form to another.

Examples

Energy in a speaker is converted from Electrical Energy to Sound energy.

Energy in a Cycle is converted from Muscular energy to Mehcanical energy.

Verification

Consider an object of mass 'm' at a height 'h', from the ground with 'g' as 10m/s. Let us consider the energy shown by the object at three stages  A, B and C

[Refer Picture for Heights]

Total energy at A

Ep = mgh

Ek = 0 [Since object is at rest]

Total Energy = Ek + Ep

Te = 0 + mgh

$\large\boxed{\mathbf{Te = mgh}}$ → 1

Total Energy at B

Ep = mgh

Ep = mg[h - x]

Ek = $\frac{1}{2}$ mv²

According to the 3rd law of motion,

v² - u² = 2as

v² = 2as + u²

Here, u = 0 , a = g, s = x. Substituting these values we get

v² = 2gx

Substituting this value in Ek we get,

Ek = $\frac{1}{2}$ mv²

Ek = $\frac{1}{2}$ m × 2gx

2 and 2 get cancelled.

Ek = mgx

Total Energy = Ep + Ek

Te = mg [h - x] - mgx

Te = mgh - mgx - mgx [mgx is cancelled]

$\large\boxed{\mathbf{Te = mgh}}$  → 2

Total Energy at C

Ep = 0

Ek = $\frac{1}{2}$ mv²

According to 3rd Law of Motion,

v² - u² = 2as

v² = 2as - u²

Here, u = 0 , a = g, s = h. Substituting these values we get

v² = 2gh

Substituting this value in Ek we get,

Ek = $\frac{1}{2}$ mv²

Ek = $\frac{1}{2}$ m × 2gh

2 and 2 get cancelled.

Ek = mgh

Total Energy = Ep + Ek

Te = 0 + mgh

$\large\boxed{\mathbf{Te = mgh}}$  → 3

Conclusion

From 1, 2 and 3 we can say the, energy is the same at all three stages.

Therefore Law of Conservation of Energy is verified!

-------------------------

Remember, Law of conservation of energy cannot be proved, but only verified!

------------------------

$\mathbb{THANKS!}$

Hope It Helps!

#BeBrainly