What is the change in potential energy (in calories) of a `10 kg` mass after `41.8 m` fall?

Options

A. `1000 cal`
B. `800 cal`
C. `1500 cal`
D. `2000 cal`

Answer

A

Explanation

Change in potential energy
`Delta U = mgh = 10xx10xx41.8=4180J`
If mechanical work//energy `(W)` in joule produces the same temperature as heat `(H)` , we write,
`W=JH`
where `J=4.18` is called mechanical equivalent of heat. `J` is expressed in joule//calorie.
Hence equivalent calories will be
`H=(Delta U)/(J) = (4180)/(4.18) = 1000 cal`.