Rotational Motion Question 8
Question 8 - 29 January - Shift 1
A solid sphere of mass $2 kg$ is making pure rolling on a horizontal surface with kinetic energy $2240 J$. The velocity of centre of mass of the sphere will be $ms^{-1}$.
Show Answer
Answer: (40)
Solution:
Formula: Centre of Mass
$KE=\frac{1}{2} mv^{2}+\frac{1}{2} I \omega^{2}$
$2240=\frac{1}{2} 2(v)^{2}+\frac{1}{2} \frac{2}{5}(2) R^{2} \cdot(\frac{v}{R})^{2}$
$2240=v^{2}+\frac{2}{5} v^{2}$
$\Rightarrow v=40 m / s$
