Two blocks A (2 kg) and B (4 kg) are connected by a string passing over a smooth pulley. B rests on a rough horizontal surface and A rests on B. The coefficient of friction between A and B is the same

Question

Two blocks A (2 kg) and B (4 kg) are connected by a string passing over a smooth pulley. B rests on a rough horizontal surface and A rests on B. The coefficient of friction between A and B is the same as that between B and the horizontal surface, both being $0.4$ . The minimum horizontal force needed to move A to the left is: (Take $g = 10$ m/s²)

Options:

Answer:

B

Solution:

On B
$T = 0.4 (2) (10) + 0.4 (6) (10) = 8 + 24 = 32 N .$
On A
$F = T + 0.4 (2) (10) = 32 + 8 = 40 N .$
Option B.

TestHub · Accepted Answer

On B T = 0.4 ( 2 ) ( 10 ) + 0.4 ( 6 ) ( 10 ) = 8 + 24 = 32 N . On A F = T + 0.4 ( 2 ) ( 10 ) = 32 + 8 = 40 N . Option B.

Physics - NLM Question with Solution | TestHub

Options:

Doubts & Discussion