Physics-
General
Easy
Question
The moment of inertia of a body about a given axis is 1.2 kg × m2. Initially, the body is at rest. In order to produce a rotational KE of 1500 joule, an angular acceleration of 25 rad/sec2 must be applied about that axis for a duration of -
- 4 s
- 2 s
- 8 s
- 10 s
The correct answer is: 2 s
KR = 
I2 = I (t)2 = I2t2
1500 = × 1.2 × (25)2t2
or t2 = 4 or t = 2s
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