What forces act on the cars of a roller coaster when they enters loops and turns after reaching the initial summit?

Question

anonymous · Answer

G FORCE

anonymous · Answer

probably 
1)gravity
2)normal contact force between car and track

shane_b · Answer

In addition to what @Dikawar said, centripetal force would also be acting on the cars.

anonymous · Answer

@Shane_B
Centripetal force in not a different force like gravity, friction, contact force. It is provided by these forces. In this case, vectorial sum of gravity and contact force will equal centripetal force.

shane_b · Answer

Overthinking it...