Question

11.
Two blocks A (1 kg) and B (3 kg) are connected by
a string passing over a smooth pulley as shown. B
rests on rough horizontal surface and A rest on B.
The co-efficient of friction between A and B is the
same as that between B and the horizontal sur-
face. The minimum horizontal force Frequired to
move A to the left is 24 N. The co-efficient of friction
is (g = 10m/s2)
1kg
B
3kg
(A) 0.67
(B) 0.5
(C)0.4
(D) 0.25​

Answer 1

Explanation:

For block B

T=f1.......f(frictional force)

f1=mu×30...(1)...mu×N...mu is coefficient of friction

For A

T+f2=24.......as T will be same

f2=mu×40

from here eliminate T and coefficient can be calculated