The specific heat of solids at low temperatures varies with absolute temperature `T` according to the relation `S=AT^(3)`, where `A` is a constant. The heat energy required to raise the temperature of a mass m of such a solid from `T=0` to `T=20K` is:

Options

A. `4xx10^(4)mA`
B. `2 xx 10^(4)mA`
C. `8xx10^(6)mA`
D. `2xx10^(6)mA`.

Answer

A

Explanation

`Q=int_(0)^(20)mS" "dT=int_(0)^(20)(AT^3)dT=4xx10^(4)mA`.