Mini-Quiz: Rollers are Friction-Reducing Machines

1. Why is it difficult to drag a heavy object across the ground?

   The friction is usually greatThat is correct. You know about rollers. There are no handles to hold ontoSorry, not correct. Try another button. You are too weak to do the jobGood try, but not right. Select another answer.

2. How do rollers make it easier to move a heavy object?

   You are going downhillOops! Wrong answer. Re-read the question and try again. You can power the rollersSorry, not correct. Try another button. Friction is much less using rollersCorrect. You are smart!

3. What is a simple way to calculate the mechanical advantage?

   Divide sliding coefficient of friction by rolling coefficientThat is correct. You know about rollers. Divide rolling coefficient of friction by sliding coefficientGood try, but not right. Select another answer. Divide force mechanical advantage by rolling coefficientOops! Wrong answer. Re-read the question and try again.

Pick an answer to see instant feedback. Re-read the lesson if you miss one.