Question

If kinetic energy is doubled, find fractional change in momentum :

• A. $\sqrt{2}$
• B. $2\sqrt{2}$
• C. $\frac{1}{\sqrt{2}}$
• D. $\frac{1}{2\sqrt{2}}$

Answer 1

Answer: (A)

$KE=\frac{p^2}{2m}\Rightarrow KE\propto p^2$
$\Rightarrow \frac{p_2}{p_1}=\sqrt{\frac{K{E}_2}{K{E}_1}}=\sqrt{2}$