OnlineCBT
Physics · SYSTEMS OF PARTICLES AND ROTATIONAL MOTION
हिन्दीA wheel rotating about a fixed axis with an initial angular speed of \( 20\text{ rad/s} \) is decelerated uniformly at \( 2\text{ rad/s}^2 \). The ratio of the tangential acceleration to the centripetal acceleration of a point on the rim at \( t = 5\text{ s} \) (radius of the wheel = \( 0.2\text{ m} \)) is:
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Correct answer · Option B
\( 0.02 \)
Explanation
At \( t = 5\text{ s} \), \( \omega = \omega_0 - \alpha t = 20 - 2(5) = 10\text{ rad/s} \). Centripetal acceleration \( a_c = \omega^2 r = (100)(0.2) = 20\text{ m/s}^2 \). Tangential acceleration magnitude \( a_t = \alpha r = 2(0.2) = 0.4\text{ m/s}^2 \). Ratio \( a_t / a_c = 0.4 / 20 = 0.02 \).
