COMEDK · Physics · 8. Rotational Motion
A body of mass \(5 \mathrm{~kg}\) at rest is rotated for \(25 \mathrm{~s}\) with a constant moment of force \(10 \mathrm{~Nm}\). Find the work done if the moment of inertia of the body is \(5 \mathrm{~kg} \mathrm{~m}^2\).
- A 6250 J
- B 125 J
- C 1250 J
- D 625 J
Answer & Solution
Correct Answer
(A) 6250 J
Step-by-step Solution
Detailed explanation
Given the moment of force (torque) \(\tau = 10 \text{ Nm}\), moment of inertia \(I = 5 \text{ kg m}^2\), and time \(t = 25 \text{ s}\). The angular acceleration \(\alpha\) is given by \(\tau = I \alpha\). \(\alpha = \dfrac{\tau}{I} = \dfrac{10}{5} = 2 \text{ rad/s}^2\). Since…
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