Question

Blocks A and B in Figure are connected by a bar of negligible weight. If mass of A and M are 170 kg each and  µ_A = 0.2 and µ_B = 0.4 , where µ_A and µ_B are the coefficients of limiting friction between blocks and plane, calculate the force in the bar. (g = 10 m/s²)

(A) 150 N 

(B) 75 N 

(C) 200 N 

(D) 250 N

Answer 1

Correct option is (A) 150 N

Here both the particles are constrained to move together.

Hence a_A = a_B Now let us first find the net force down the incline;

i.e (m₁ + m₂)g sin θ

i.e. force in the bar is 150 N.

Answer 2

correct answer is (A)  150 N