An inextensible cord connects two blocks A and B of mass 2 k

An inextensible cord connects two blocks, A and B, of mass 2 kg and 4 kg respectively. The cord is able to slide along the edge of the hole with negligible friction.

Solution

That the turntable speeds up very slowly means that we can ignore any tangential acceleration of the coin. All we have to consider is the centripetal acceleration. The force for centripetal acceleration is provided by the force of static friction. m2 r = µsN m2 r = µsmg 2 r = µsg 2 = 0.8 × 9.8/0.15 = 52.267 or = 7.23 rad/s. Converting to rpm, 7.23 rad/s=7.23/2 × 60 rpm = 69 rpm. Thus, at 60 rpm the coin will not slide off the turntable.