A roller coaster has a mass of 585 kg when fully loaded with passengers. A)If the vehicle has a speed of 18.0 m/s at point a, what is the force (in N) of the track on the vehicle at this point?
B) What is the maximum speed (in m/s) the vehicle can have at point B in order for gravity to hold it on the track?
Point A says the radius is 10m. Point B says radius is 15m.

Explanation:

I'm going to ASSUME that point A is at the bottom of a circular curve.

The track must support the weight of the car and also supply the needed centripetal force

F = mg + mv²/R

F = 585(9.81 + 18.0²/10) = 24,692.85

F = 24.7 kN

I'm going to ASSUME that point B is at the top of a circular curve.

The track must support the weight of the car and also supply the needed centripetal force.

At a minimum, the weight can be reduced to zero and all the gravity acceleration acts as centripetal acceleration.

0 = mg - mv²/R

        g = v²/R

         v = √Rg = √(15(9.81) = 12.1305399...

        v = 12.1 m/s

f=ma newton

f=100x2.5=250n

the answer you are looking for is d. there are no holes for blood to enter or leave the system. your welcome