A ball rolled over a shallow step will experience an increase in velocity along the direction perpendicular to the step. This causes a deflection in the ball’s trajectory. In this paper, we derive the equations that describe the motion of a ball rolled over a shallow step and present the results of our experimental test. This simple demonstration can be used in any classroom where the physics teacher has access to a ball and a stack of papers. Prior work has shown that a ball rolled over an edge can maintain its speed, as is commonly assumed, but it can also experience an increase or even decrease in speed.1,2 The ball can either roll without slipping while it is in contact with the edge, or else begin to slip before it leaves the edge.3 In this paper, we will consider the case where the ball rolls without slipping...

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