Laws of Motion

JEE Main level, single correct, medium

185 of 210

Question 185 of 210

A block A of mass 4 kg is placed on another block B of mass 5 kg, and the block B rests on a smooth horizontal table. If the minimum force that can be applied on A so that both the blocks move together is 12 N, the maximum force that can be applied on B for the blocks to move together will be :

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Answer: (A) 0 N

There is an error in this question. Given a smooth horizontal table, there would be no friction between the table and the lower (5 kg) block. As a result the "minimum" force on the upper (4kg) block for both blocks to move together would be 0 N.

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