Question

For the arrangement shown in figure the coefficient of friction between the two block is $\mu$. If both the blocks are identical and moving, then the acceleration of each block is:

• A. $\frac{F}{2m}-2\mu g$
• B. $\frac{F}{2m}$
• C. $\frac{F}{2m}-\mu g$
• D. $zero$

Answer 1

Answer: (C)

$\frac{F}{2m}-\mu g$

Friction acts on the upper block towards right, and its reaction pair acts towards the left on the lower block.

Considering forces acting on the upper block,

$T-\mu mg=ma$

Considering forces acting on the lower block,

$F-\mu mg-T=ma$

From the two equations,

$a=\frac{F}{2m}-\mu g$