Q5.34 Two bodies A and B of masses 5 kg and 10 kg in contact with each other rest on a table against a rigid wall (Fig. 5.21). The coefficient of friction between the bodies and the table is 0.15. A force of 200 N is applied horizontally to A. What are (a) the reaction of the partition? What happens when the wall is removed? Ignore the difference between \mu_s and \mu_k.


Answers (1)

The applied force is 200 N.

The maximum friction force on the system is given by :

                                           F\ =\ \mu \left ( m_A\ +\ m_B \right )g

or                                              =\ 0.15 \left ( 5\ +\ 10 \right )g=\ 22.5\ N

So the net force on partition is  200  -  22.5  =  177.5  N.

This will be equal to the reaction of the partition (action-reaction pair). The direction will be leftward.