Final answer:
The correct option for the forces in a free-body diagram for a motorcycle looping the loop is option 2, which includes tension force, normal force, gravitational force, and centripetal force. Centripetal force is the net force toward the center during circular motion. Centrifugal force is not a real force and friction is negligible in an ideal loop-the-loop.
Step-by-step explanation:
The correct answer for the force body diagram for a motorcycle looping the loop is tension force, normal force, gravitational force, centripetal force. When an object is moving in a circular path, such as a motorcycle in a loop-the-loop, there is a force that acts towards the center of the circle keeping the object in circular motion. This is known as the centripetal force. In this scenario, the normal force and the gravitational force contribute to the centripetal force needed to keep the motorcycle on its path. Therefore, option 2 is correct.
To create a free-body diagram, you will need to consider all the forces acting on the motorcycle, which includes the tension force (if any), the normal force exerted by the track, the gravitational force (weight of the motorcycle), and the centripetal force due to circular motion. Remember that centripetal force is not an additional force but is the net force towards the center required for circular motion. It results from the vector addition of the actual forces, such as normal and gravitational forces, in the case of a loop-the-loop.
It's important to note that 'centrifugal force' is often considered a 'fictitious' force because it is not an actual force but rather a result of inertia from the perspective of a rotating reference frame and is not included in a free-body diagram. Finally, friction can play a role if the motorcycle's tires are interacting with the surface, but in a perfectly smooth loop-the-loop without any sliding or resistance, it may be negligible.