The internal energy of a solid also increases when heat is transferred to it from its surroundings. A 5 kg solid bar is heated at atmospheric pressure. Its temperature increases from `20^@C` to `70^@C`. The linear expansion coefficient of solid bar is `1xx10^(-3)//^(@)C`. The density of solid bar is `50 Kg//m^3`. The specific heat capacity of solid bar is `200 J//kg C^@`. The atmospheric pressure is `1xx10 N//m^2`.
The increase in the internal energy of the sold bar is

Options

A. 49500 J
B. 48500 J
C. 49000 J
D. 50000 J

Answer

B

Explanation

`DeltaU=Q-W=50000-1500=48500J`