Mini-Quiz: Normal Force in Sliding Friction

1. When is the normal force equal to the weight of an object?

   When the object is on a level planeThat is correct. You undertstand normal friction force. It is actually equal to the mass of the objectSorry, not correct. Try another button. It depends on the direction of motionGood try, but not right. Select another answer.

2. As the angle of an incline increases, what happens to the normal force, as affected by gravity?

   It increases until it gets to infinitySorry, not correct. Try another button. Nothing, because normal force has nothing to do with the inclineOops! Wrong answer. Re-read the question and try again. It decreases until it reaches zero at a vertical inclineCorrect. You sure are smart.

3. What is an example of creating an external normal force?

   Increasing the incline of the planeGood try, but not right. Select another answer. Pushing the two objects togetherThat is correct. You undertstand normal friction force. Changing the coefficient of frictionOops! Wrong answer. Re-read the question and try again.

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