This weekend, I went the Punahou Carnival and saw a lot of physics. The ride called the ring of fire is a ride that takes you in a loop. It slowly speeds up until you only have enough speed to make a full revolution. This ride reminded me of centripetal force. The equation for Fc=mass times velocity squared over the radius of the circle. The roller coaster feels normal force from the tracks and that helps the centripetal force. At the highest point at the slowest speed the normal force of the track is zero.