A roller coaster is going through a vertical loop (diameter 35 m) at a constant speed. How fast should the roller coaster be going so the passengers will feel no
more than 3.5 times their normal weight at the bottom of the loop? What force
will they feel from the seat at the top of the loop? What force would they feel halfway between the top and the bottom of the loop?

The period of a pendulum varies directly as the square root of the length of the pendulum and inversely as the square root of the acceleration due to gravity. find the period when the length is 144 cm and the acceleration due to gravity is 980 cm per second squared, if the period is 7pi seconds when the length is 289 cm and the acceleration due to gravity is 980 cm per second squared.