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Physics · SYSTEMS OF PARTICLES AND ROTATIONAL MOTION
हिन्दीA motor wheel begins to rotate from rest with a uniform angular acceleration \( \alpha \). If it completes \( n_1 \) revolutions in the first \( t \) seconds and an additional \( n_2 \) revolutions in the next \( t \) seconds, then the ratio \( n_2 / n_1 \) is:
Correct answer · Option 4
3
Explanation
\( \theta_1 = \frac{1}{2}\alpha t^2 \propto n_1 \). Total displacement in time \( 2t \) is \( \theta_{2t} = \frac{1}{2}\alpha (2t)^2 = 4 \theta_1 \). Therefore, displacement in the second interval is \( \theta_2 = 4\theta_1 - \theta_1 = 3\theta_1 \implies n_2 / n_1 = 3 \).
