What types of force will make a roller coaster turn through loop?

A combination of gravitational force and centripetal force will cause a roller coaster to turn through a loop-de-loop.

1. Gravitational force: This is the force that pulls the roller coaster downwards towards the ground. It acts through the centre of mass of the roller coaster and is always in the downwards direction.

2. Centripetal force: This is the force that pushes the roller coaster around the curved path of the loop. It is directed towards the centre of the curve and is equal in magnitude to the gravitational force.

When the roller coaster is at the top of the loop, the gravitational force is acting downwards and the centripetal force is acting upwards. These two forces are equal in magnitude and so the roller coaster remains in a circular path.

As the roller coaster moves down the loop, the gravitational force continues to act downwards and the centripetal force continues to act upwards. However, the gravitational force is now greater in magnitude than the centripetal force. This causes the roller coaster to accelerate downwards.

At the bottom of the loop, the gravitational force is still acting downwards and the centripetal force is still acting upwards. However, the gravitational force is now smaller in magnitude than the centripetal force. This causes the roller coaster to slow down and eventually come to a stop.

The roller coaster then continues to move up the other side of the loop, and the cycle of forces is repeated.