A block of mass m is placed on another block of mass M lying on a smooth horizontal surface as shown in the figure. The co-efficient of friction between the blocks is `mu`. Find the maximum horizontal force F (in Newton) that can be applied to the block M so that the blocks together with same acceleration? `(M=3kg, m=2kg, mu=0.1, g=10m//s^(2))`

Explanation

When both blocks move together `a=(F)/(M+m)`
From FBD of m relative to M for both blocks to move together

`ma lt f`
`m((F)/(M+m))lt mu mg`
`F lt (M+m)mu mg`
`F lt (M+m) mu g`
`F lt 5N`
`therefore F_("max")=5N`