A mass of 12.2 kg is attached to a string which is wrapped around a cylindral spool of radius 10 cm and moment of inertia 4.00 kg* m square. The spool is suspended from the ceeling and is free to rotate about its central axis. a) after the mass is released from the res what is its downward acceleration? b)If it is dropped from a height of 5.00 m how long will it take to hit the ground?