If an object has the moment of inertia of 1 kgm2 and it rotates with a constant angular velocity of 2 rad/s, then the rotational kinetic energy of the object will be
Correct answer: B. 2 J
- A. 0.5 J
- B. 2 J
- C. 4 J
- D. 8 J
Explanation
The rotational kinetic energy is calculated using the formula KE = 0.5 * I * ω². Here, the moment of inertia (I) is 1 kgm² and the angular velocity (ω) is 2 rad/s. Substituting these values into the formula gives KE = 0.5 * 1 * (2)² = 0.5 * 1 * 4 = 2 J. Therefore, the correct answer is 2 J. The other options result from incorrect application of the formula or arithmetic errors.
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Rotational motion relates angular displacement, angular velocity and angular acceleration to linear displacement, tangential velocity and tangential acceleration through the radius. Questions use radians, v equals r omega and tangential acceleration, while distinguishing tangential velocity from centripetal acceleration and angular quantities from their linear counterparts.
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