Question

The coefficient of static friction between the two blocks shown in figure is $\mu$ and the table is smooth.What maximum horizontal force F can be applied to the block of mass M so that the blocks move together?

Answer 1

$N=mg$

$fs=MgCl$

$fs=ma$ ....(i)

$N^{\prime }=mg+mg$

$f-fs=Ma$ ...(ii)

from (i) & (ii) we get

$f-ma=Ma$

$f=a(m+M)$$

from (i); $MgCl=ma$

$\Rightarrow a=gCl$

so, $f=gCl(m+M)$