JEE Mains · Physics · STD 11 - 5. work,energy,power and collision
A bullet of \(10\, {g}\), moving with velocity \(v\), collides head-on with the stationary bob of a pendulum and recoils with velocity \(100 \, {m} / {s}\). The length of the pendulum is \(0.5\, {m}\) and mass of the bob is \(1\, {kg}\). The minimum value of \(v=\) \(....{m} / {s}\) so that the pendulum describes a circle. (Assume the string to be inextensible and \({g}=10\, {m} / {s}^{2}\) )
- A \(1000\)
- B \(400\)
- C \(100\)
- D \(10\)
Answer & Solution
Correct Answer
(B) \(400\)
Step-by-step Solution
Detailed explanation
\({V}^{\prime}=\sqrt{5 {gR}}=\sqrt{5 \times 10 \times 0.5}\) \({V}^{\prime}=5\, {m} / {s}\) \({m}_{1} {V}={m}_{2} \times 5-{m}_{1} \times 100\) \(\frac{10}{1000} \times {V}=5-\frac{10}{1000} \times 100\) \({V}=400\, {m} / {s}\)
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