Physics

Physics

Problem

A horizontal block is acted upon by a force of fixed magnitude FF that can be applied either at 30∘30^{\circ} above the horizontal (pull) or at 30∘30^{\circ} below the horizontal (push). The surface has the same coefficient of static friction μs\mu_s in both cases. Which statement describes which orientation will make the block start moving first? a) Pushing at 30∘30^{\circ} below the horizontal requires the smaller force to initiate motion. b) Pulling at 30∘30^{\circ} above the horizontal requires the smaller force to initiate motion. c) Both pulling and pushing require the same minimum force to initiate motion. d) Pulling at 30∘30^{\circ} above the horizontal actually needs a larger force because some of the pull is wasted in lifting the block.

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