Question

answer me this question

Answer 1

Acceleration of the 4 kg block is 2 times that of the 2 kg block. Because the string connecting them moves twice at 4 kg block.

acceleration of the 2 kg block = a.
Given,   0.3² = 0 + 2 * a * 2 
             a = 0.0225 m/s²

Now, let the tension in the string be T.

For 4 kg block:      T - μ * 4 * 10 = 4 * (2*0.0225) 
                              T = 40 μ + 0.18    ---(1)

For 2 kg block:      2 *10 - 2 T = 2 * 0.0225
                              T = 9.9775 Newtons  ---(2)

From 1 and 2 ,   we get    μ = 0.245 (approx).