Block P of mass 4.0kg rests on a 30∘ rough incline. It is connected by a light string that passes over a frictionless pulley at the top of the incline to a vertically hanging block Q of mass 1.0kg. The coefficient of kinetic friction between block P and the incline is 0.20. The system is released from rest, and block P moves down the slope. Take g=9.8m/s2. What is the magnitude of the acceleration of the system?
a) 1.96m/s2
b) 0.60m/s2
c) 3.3m/s2
d) 0.39m/s2