JEE Mains · Physics · STD 11 - 6. system of particles and rotational motion
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 \(..........ms ^{-1}\).
- A \(40\)
- B \(38\)
- C \(37\)
- D \(36\)
Answer & Solution
Correct Answer
(A) \(40\)
Step-by-step Solution
Detailed explanation
\(KE =\frac{1}{2} mv ^2+\frac{1}{2} I \omega^2\) \(2240=\frac{1}{2} 2( v )^2+\frac{1}{2} \frac{2}{5}(2) R ^2 \cdot\left(\frac{ v }{ R }\right)^2\) \(2240= v ^2+\frac{2}{5} v ^2\) \(\Rightarrow v =40\,m / s\)
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