Engineering Board Exam Reviewer · Engineering Mechanics · hard
A solid cylinder of mass 5 kg and radius 0.3 m spins about its central axis at an angular velocity of 7 rad/s. What is its rotational kinetic energy?
- 11.025
- 5.9535
- 5.0715
- 5.5125
Answer
D. 5.5125
Solution
I = 1/2mr2 = 1/2(5)(0.3)2 = 0.225 kg· m2. Rotational KE = 1/2I 2 = 1/2(0.225)(7)2 = 5.5125 J.
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