Question

use the information and diagram to answer the following question.
in a lab investigation, students flick a marble inside of a wooden hoop and the marble rolls in a circular path
along the edge of the hoop. as soon as the students remove the hoop, the
marble rolls in a straight - line path
which of the following forces supplies the centripetal force to the marble
when it travels in a circular path?
above view
path with hoop
path without hoop
the normal force between the marble and the hoop
the gravitational force between the table and the marble
the normal force between the table and the marble
the frictional force between the marble and the hoop

Explanation:

1. Centripetal force is the force that keeps an object moving in a circular path, directed towards the center of the circle.
2. For the marble moving in a circular path along the hoop:

• The gravitational force between the table and the marble acts vertically (downward), not towards the center of the circular path of the marble, so it can't be the centripetal force.
• The normal force between the table and the marble also acts vertically (upward), perpendicular to the horizontal circular motion of the marble, so it's not the centripetal force.
• The frictional force between the marble and the hoop would act opposite to the direction of motion (tangentially), not towards the center, so it's not the centripetal force.
• The normal force between the marble and the hoop: When the marble is moving along the inside of the hoop, the hoop exerts a normal force on the marble towards the center of the circular path (since the marble is trying to move in a straight line due to inertia and the hoop pushes it towards the center to keep it in circular motion). This normal force provides the centripetal force required for the circular motion.

Answer:

The normal force between the marble and the hoop