In: Physics
A) the moment of inertia of the entire spool = 1/2 * 4.00 * 0.52 + 4 * 0.52
= 1.5 kg.m2
B) Applying conservation of energy -
=> 4 * 9.8 * 5 = 1/2 * 4 * v2 + 1/2 * 1.5 * (v/0.5)2
=> v = 6.26 m/s
Thus, velocity of the block before it hits the ground = 6.26 m/s
C) long does it take the block to drop = 6.26/3.918
= 1.597 sec