Quiz 8: Rotational Motion and Equilibrium
Yes , I agree that an object can have both translational kinetic energy and rotational kinetic energy at a time. A moving object will have linear velocity, so it possesses translation kinetic energy and a rotating object will have angular velocity, so it possesses rotational kinetic energy. If an object rolls on a level surface without slipping, then it possesses linear velocity due to its translation motion and angular velocity due to its rolling motion. Hence, the object has both translational kinetic energy and rotational kinetic energy.
The mud flies off when the wheel is at the o'clock position. At the o'clock position, the tangential speed is in a direction, straight upward. So the mud is in a state of free-fall body with an initial upward velocity. The mud will rise upward, reach a maximum height, and then fall back down.
A rigid body is an object or a system of particles in which the distance between any two particles is fixed. Option (a) is correct answer because in pure rotational motion all of the particles of the object have the same instantaneous angular velocity. Option is not correct because in pure rotational motion all the particles of a body have not the same tangential velocity because different particles are at different distances from the axis. Option is not correct because in pure rotational motion the acceleration is not always zero as the velocity of the particles changes continuously. Option is not correct because in pure rotational motion all particles in the body rotate about the same axis.