Answer Happy

A block (mass=2.4 kg) is hanging from a massless cord that is wrapped around a pulley (moment of inertia = 1.6 x 103 kg-m²), as the figure shows. Initially the pulley is prevented from rotating and the block is stationary. Then, the pulley is allowed to rotate as the block falls. The cord does not slip relative to the pulley as the block falls. Assume that the radius of the cord around the pulley remains constant at a value of 0.045 m during the block's descent. Find (a) the angular acceleration of the pulley and (b) the tension in the cord. (a) Number (b) Number i Units Units 11
The drawing shows the top view of two doors. The doors are uniform and identical. Door A rotates about an axis through its left edge. and door B rotates about an axis through its center. The same force is applied perpendicular to each door at its right edge, and the force remains perpendicular as the door turns. No other force affects the rotation of either door. Starting from rest, door A rotates through a certain angle in 3.20 s. How long does it take door B (also starting from rest) to rotate through the same angle? Axis Number Door A Axis Door B Units