Question

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

• A. μg
• B. g/μ
• C. μ/g
• D.

Answer 1

The correct option is A

μg

There is no friction between the body B and surface of the table. If the body B is pulled with force F then
$F=(m_A+m_B)a$
Due to this force upper body A will feel the pseudo force in a backward direction.
But due to friction between A and B, body will not move. The body A will start moving when pseudo force is more than friction force.
i.e. for shopping, $m_{A}a=\mu m_{A}g\therefore a=\mu g$