Work Power Energy Question 6

Question 6 - 30 January - Shift 2

A body of mass $2 \mathrm{~kg}$ is initially at rest. It starts moving unidirectionally under the influence of a source of constant power $P$. Its displacement in $4 s$ is $\frac{1}{3} \alpha^{2} \sqrt{P} m$. The value of $\alpha$ will be

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Answer: (4)

Solution:

Formula: Relation between Momentum and Kinetic Energy

$\frac{1}{2} mV^{2}=Pt$

$V=\sqrt{\frac{2 Pt}{m}}$

$\frac{dx}{dt}=\sqrt{\frac{2 Pt}{m}}$

$x=\sqrt{\frac{2 P}{m}} \frac{2}{3}[t^{3 / 2}]_0^{4}$

$x=\frac{16 \sqrt{P}}{3}=\frac{1}{3} \times 16 \sqrt{P}$

$\alpha=4$