JEE Mains · Physics · STD 11 - 5. work,energy,power and collision
A body of mass \(2\,kg\) is initially at rest. It starts moving unidirectionally under the influence of a source of constant 10.Power P. Its displacement in \(4\,s\) is \(\frac{1}{3} \alpha^2 \sqrt{ P } m\). The value of \(\alpha\) will be \(.............\)
- A \(1\)
- B \(2\)
- C \(4\)
- D \(3\)
Answer & Solution
Correct Answer
(C) \(4\)
Step-by-step Solution
Detailed explanation
\(\frac{1}{2} mV ^2= Pt\) \(V =\sqrt{\frac{2 Pt }{ m }}\) \(\frac{ dx }{ dt }=\sqrt{\frac{2 Pt }{ m }}\) \(x =\sqrt{\frac{2 P }{ m } \frac{2}{3}}\left[ t ^{3 / 2}\right]_0^4\) \(x =\frac{16 \sqrt{ P }}{3}=\frac{1}{3} \times 16 \sqrt{ P }\) \(\alpha=4\)
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