Block a of Mass 5

Multiple Choice

Block A of mass 5.0 kg and block X are attached to a rope which passes over a pulley,as shown in the figure.An 80-N force P is applied horizontally to block A,keeping it in contact with a rough vertical face.The coefficients of static and kinetic friction between the wall and block A are μ_s = 0.40 and μ_k = 0.30.The pulley is light and frictionless.The mass of block X is adjusted until block A moves upward with an acceleration of 1.6 m/s².What is the mass of block X?

A) 9.9 kg
B) 9.3 kg
C) 8.7 kg
D) 8.1 kg
E) 7.5 kg