question_answer

Three identical blocks, each having a mass M, are pushed by a force F on a frictionless table as shown in Fig 3(a).2S. What is the acceleration of the blocks? What is the net force on the block A? What force does A apply on B? What force does B apply on C? Show action-reaction pairs on the contact surfaces of the blocks.

Answer:

                                                               If a is the common acceleration, then \[F=3M\times a\] or \[a=\frac{F}{3M}\] Net force on block A, \[{{F}_{1}}=3M\times a=3M\times \frac{F}{3M}=F\] Force applied by A on B, \[{{F}_{2}}=(M+M)a=2M\times \frac{F}{3M}=\frac{2F}{3}\] Force applied by B on C \[{{F}_{3}}=M+a=M\times \frac{F}{3M}=F/3\] The action reaction forces are shown in Fig. 3(a).26.