Rotational Motion

In rotational motion, the work done by a constant torque is given by: where: - is the constant torque (10 Nm), - is the angular displacement.
Step 1: Find angular displacement
Since the body starts from rest and is rotated for 25 seconds under a constant moment of force (torque), we can use the equation for angular displacement under constant angular acceleration: where: - is the initial angular velocity (which is 0 since the body starts from rest), - is the time (25 s), - is the angular acceleration. Since (where is the moment of inertia), the angular acceleration is: Substituting and , we get: Now, substitute and into the equation for :
Step 2: Calculate the work done
Now, substitute the values of and into the work equation: Thus, the work done is 6250 J, which corresponds to option (C).