If this were actually true, we should see the following behavior. (In this
discussion, let's assume that .)
- If the ramp were inclined at 45 degrees, the block would not move.
At this angle, friction would exactly cancel out gravity. (The exact angle at
which this happens depends upon the coefficient of friction.)
- For angles greater than 45 degrees, the block would move down the ramp,
but more slowly than before. This certainly fits with our intuition.
- For angles less than 45 degrees, the block would move backwards, up
the ramp! Your everyday experience, of course, tells you that this is not what
would actually happen.
Return to lesson.
Joseph L. Zachary
Department of Computer Science
University of Utah