Question Detail
Question
In a stationary engine, the moment of inertia is 30 kg m². What is the kinetic energy if its angular acceleration is 4 rad/s²?
Correct Answer
Option D is the correct answer.
Detailed Explanation
The engine is stationary, so its angular velocity is zero. Kinetic energy of rotation is KE = ½ I ω². Since ω = 0, the kinetic energy is 0 J regardless of the angular acceleration. Angular acceleration does not directly give kinetic energy without knowing the angular velocity.
Hint
Kinetic energy depends on the square of angular velocity. If the object is stationary, its kinetic energy is zero.