Question

can anyone help me to solve with explain stions​

Answer 1

Answer:

12 m

Explanation:

We will have to use energy convservation since there was no external force:

Mechanical (initial) = Mechanical (final)

U1 + 0 = U2 + K

=> K = U1 - U2 = loss

=> K = mgH where H is the height which it falls.

Now object loses 40% potential energy.

So K =2U/5

⇒ K = 2U/5

⇒ K = 2× 900 =1800 J

1800 = 15×10×H

⇒ H = 180/15

⇒ H = 12m (ans)