Question 70: Centre of Mass and Rotational Motion

Question

A spherical body of mass $100 \mathrm{~g}$ is dropped from a height of $10 \mathrm{~m}$ from the ground. After hitting the ground, the body rebounds to a height of $5 \mathrm{~m}$. The impulse of force imparted by the ground to the body is given by : (given, $\mathrm{g}=9.8 \mathrm{~m} / \mathrm{s}^2$)

Accepted Answer

$\begin{aligned}
\vec{I} & =\Delta \vec{P}=\vec{P}_f-\vec{P}_i \
\mathrm{M} & =0.1 \mathrm{~kg} \
I & =\Delta P=0.1(\sqrt{2 	imes 9.8 	imes 5}-(-\sqrt{2 	imes 9.8 	imes 10})) \
& =0.1(14+7 \sqrt{2}) \approx 2.39 \mathrm{~kg} \mathrm{~ms}^{-1}
\end{aligned}$

Answer

$43.2 \mathrm{~kg} \mathrm{~ms}^{-1}$

Answer

$2.39 \mathrm{~kg} \mathrm{~ms}^{-1}$

Answer

$4.32 \mathrm{~kg} \mathrm{~ms}^{-1}$

Answer

$23.9 \mathrm{~kg} \mathrm{~ms}^{-1}$

Centre of Mass and Rotational Motion

A spherical body of mass 100 \mathrm{~g} is dropped from a height of 10 \mathrm{~m} from the ground. After hitting the ground, the body rebounds to a height of 5 \mathrm{~m}. The impulse of force imparted by the ground to the body is given by : (given, \mathrm{g}=9.8 \mathrm{~m} / \mathrm{s}^2)

Choose the correct answer: