Question

A system consists of three masses m₁ , m₂ and m₃ connected by a string passing over a pulley P. The mass m₁ hangs freely and m₂ and m₃ are on a rough horizontal table (the coefficient of friction = μ ). The pulley is frictionless and of negligible mass. The downward acceleration of mass m₁ is (Assume m₁ = m₂ = m₃ = m).

(a) g(1-gμ)/9

(b) 2 gμ/3

(c) g(1-2μ)/3

(d) g(1-2μ)/2

Answer 1

Correct option (c) g(1-2μ)/3

Explanation:

Force of friction on mass m₂ = μm₂g

Force of friction on mass m₃ = μm₃g

Let a be common acceleration of the of system.