A 50-N applied force (30° to the horizontal) accelerates a 10-kg box across a horizontal sheet
of ice (see diagram). Ben Thayer, Don Thatt, and
Warren Peace are discussing the problem. Ben
suggests that the normal force is 50 N; Don
suggests that the normal force in the diagram is
75 N; and Warren suggests that the normal force
is 100 N. While all three answers seem
reasonable, only one is correct. Which is the
correct normal force? 75 N What error are the
incorrect students likely making?