Q. A body $B$ lies on a smooth horizontal table and another body $A$ is placed on $B$. The coefficient of friction between $A$ and $B$ is $\mu$. What acceleration given to $B$ will cause slipping to occur between $A$ and $B$ ?
Laws of Motion
Solution:
There is no friction between the body $B$ and surface of the table.
If the body $B$ is pulled with force $F$, then
$F=\left(m_{A}+m_{B}\right) a$
Due to this force, upper body $A$ will feel the pseudo force in a backward direction.
$f=m_{A} \times a$
But due to friction between $A$ and $B$, the body will not move.
Body $A$ will start moving when pseudo force is more than friction force, i.e., for slipping,
$m_{ A } a=\mu m_{A} g$
$\Rightarrow a=\mu g$
