# Forces on roller coaster doing a loop

1. Jun 4, 2005

### UrbanXrisis

When a roller coster does a loop, what forces do we feel at the top of the loop?

I think it's only the normal force. There is MG acting downwards, and also the normal force of the rollercoster seat that is pushing towards the center of the coster.

Is this normal force the same as the centripetal force?

2. Jun 4, 2005

### HallsofIvy

Staff Emeritus
Are you saying that we only "feel" the net force. From the wording of the question, "what forces", I would think they wanted you to give all forces. There is a force of gravity, mg, straight down, that is the centripetal force. There is one other force you may be forgetting.

3. Jun 4, 2005

### UrbanXrisis

force of gravity and normal force? they both act downwards right?

4. Jun 4, 2005

### Pyrrhus

Remember, that centripetal force is a role given to forces (or components of these forces) that act towards the center, on the case the rollercoaster is upside down on the tope of the loop, both the normal and the weight point to the -y axis.