4 . A force (F ) accelerates three blocks across a rough horizontal surface as shown in the figure. The
coefficient of friction (μ) between the blocks and the surface is the same for each block. Which of the
following statements is correct?
(A) The acceleration of all the blocks will be equal to .(B) The net force acting on each block will be the same.
(C) The net force acting on block m is the largest.
(D) The net force acting on block 2m is the largest.
(E) The net force acting on block 3m is the largest.Answers
1 . E —
2 . B —The horizontal forces acting on the block cancel each other out: Fsin θ=FN . The vertical forces
accelerate the block upward: