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An ice block at 0^(@)C is dropped from h...

An ice block at `0^(@)C` is dropped from height `'h'` above the ground. What should be the value of `'h'` so that it melts completely by the time it reaches the bottom assuming the loss of whole gravitational potential energy is used as heat by the ice? `[Given: L_(f) = 80 cal//gm]`

A

`33.6 m`

B

`33.6 km`

C

`8 m`

D

`8 km`

Text Solution

Verified by Experts

The correct Answer is:
B
Applying energy conservation:
`mgh = mL_(f)`
`h=(l_f)/(g) = (80 cal//gm)/(10 m//s^(2)) = (80xx4.2xx1000J//kg)/(10m//s^(2))`
`((336xx10^(3))/(10))(N-s^(2))/(kg) = 33.6 km`.
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