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Question
A wheel rotating at a speed of 600 rpm (revolutions per minute) about its axis is brought to rest by applying a constant torque for 10 seconds. Find the angular deceleration and the angular velocity 5 seconds after the application of the torque.
Solution
Initial angular velocity of the wheel,
\[\omega_0 = 600 rpm\]
\[ = \frac{600}{60} = 10\text{ revolutions per second}\]
After 10 seconds,
Final angular velocity of the wheel,
\[\omega = 0\]
\[\text{So, }\omega_0 = - at\]
\[ \Rightarrow \alpha = - \frac{10}{10} = - 1 rev/ s^2 \]
Now, t = 5s
We know that
\[\omega' = \omega_0 + at\]
\[ \Rightarrow \omega' = 10 - 1 \times 5 = 5 rev/s\]
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