Question

A ball of mass 50 gm is dropped from a height h = 10 m. It rebounds losing 75 percent of its kinetic energy. If it remain its constant with the ground for $\Delta t=0.01$ sec., the impulse of the impact force is

• A. ${10}^2$
• B. ${10}^3$
• C. ${10}^{-2}$
• D. ${10}^{-4}$

Answer 1

The correct option is A ${10}^2$

Mass$=5\times {10}^{-2}kg.$

$t={10}^{-}2sec.$

S(Displacement)$=10m.$

$S=ut+a{t}^2/2$

$2\times 10=0+a\left({10}^{-}4\right)$

Hence$,a=2\times {10}^5$

$Force=(5\times {10}^{-}2)(2\times {10}^5)$

$F={10}^{4}N$

We know that$,$

$Impulse=\left(Force\right).\left(time\right)$

$=\left({10}^4\right)\left({10}^{-}2\right)$

$={10}^{2}N$

Hence,

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