Foundations of Physical Science. Workshop: The Loop Track. The Loop Track. CPO Science. Key Questions. Why does a roller coaster stay on the track when it is upside down on a loop?. www.rcdb.com. Roller Coasters. The CPO Loop Track. Investigate Motion of Marble.
Workshop: The Loop Track
Case number 1: If the weight is greater than the required centripetal force, the ball moves in a tighter circle. The tighter circle takes the ball off the track and it does not catch cleanly.
Case number 2: If the weight is exactly equal to the required centripetal force, the ball follows the track perfectly and catches cleanly in the catcher.
Case number 3: If the weight is less than the required centripetal force, the ball would move in a larger circle than the track if it could. Instead, the track restrains the ball by exerting a normal force back on the ball, forcing it to follow the circle of the track tightly and the ball catches cleanly in the catcher.