A body of mass 25 kg is dragged on a horizontal rough road with a constant speed of `20 kmh^(-1)`. If the coefficient of friction is 0.5, find the heat generated in one hour. If 50% of the heat is absorbed by the body, find the rise in temperature. Specific heat of the material of the body is 0.1 cal `g^(-1).^(@)C^(-1)`.

Options

A. `39 K`
B. `59.5 K`
C. `84.5 K`
D. `11.6 K`

Answer

D

Explanation

`0.5 xx muMg xx (V xx 60 xx 60) = MSDeltaT`
`Deltat = (0.5 xx 0.5 xx 9.8 xx 2 xx (5)/(18) xx 60 xx 60)/(0.1 xx 4.186 xx 10^(3))`