A Cinder Block of Mass M = 4

Multiple Choice

A cinder block of mass m = 4.0 kg is hung from a nylon string that is wrapped around a frictionless pulley having the shape of a cylindrical shell,as shown in the figure.If the cinder block accelerates downward at 4.90 m/s² when it is released,what is the mass M of the pulley?

A) 2.0 kg
B) 4.0 kg
C) 6.0 kg
D) 8.0 kg
E) 10 kg