Question

If the kinetic energy lost is fully converted to heat then heat produced is

• A. $\frac{1}{3}m{V}^2$
• B. $\frac{2}{3}m{V}^2$
• C. $0$
• D. $\frac{1}{6}m{V}^2$

Answer 1

The correct option is D $\frac{1}{6}m{V}^2$

$K{E}_i=\frac{1}{2}m{v}^2$

$m{v}^{\prime }\cos {30}^0\times 2=mv$

$\Rightarrow \sqrt{3}{v}^{\prime }=v$

$\Rightarrow v^{\prime }=\frac{v}{\sqrt{3}}$

$ \Rightarrow y = \frac{{\lambda D}}{{3d}}\$

$k{e}_f=\frac{1}{2}m\frac{v^2}{3}\times 2$

$=\frac{m{v}^2}{3}$

$\therefore Heat=\frac{m{v}^2}{2}-\frac{m{v}^2}{3}$

$=\frac{m{v}^2}{6}$

Hence,

option $\left(D\right)$ is correct answer.