JEE Mains · Physics · STD 11 - 5. work,energy,power and collision
If a rubber ball falls from a height \(h\) and rebounds upto the height of \(h / 2\). The percentage loss of total energy of the initial system as well as velocity ball before it strikes the ground, respectively, are _______.
- A \(50 \%, \sqrt{\frac{\mathrm{gh}}{2}}\)
- B \(50 \%, \sqrt{\mathrm{gh}}\)
- C \(40 \%, \sqrt{2 \mathrm{gh}}\)
- D \(50 \%, \sqrt{2 \mathrm{gh}}\)
Answer & Solution
Correct Answer
(D) \(50 \%, \sqrt{2 \mathrm{gh}}\)
Step-by-step Solution
Detailed explanation
\(\text { Velocity just before collision }=\sqrt{2 \mathrm{gh}}\) \(\text { Velocity just after collision }=\sqrt{2 \mathrm{~g}\left(\frac{\mathrm{h}}{2}\right)}\) \(\therefore \Delta \mathrm{KE}=\frac{1}{2} \mathrm{~m}(2 \mathrm{gh})-\frac{1}{2} \mathrm{mgh}\)…
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