posted by Angela .
A roller-coaster car speeds down a hill past point A where R1 = 10.4 m and then rolls up a hill past point B where R2 = 15.6 m, as shown below.
R1 and 2 are radii
(a) The car has a speed of 21.0 m/s at point A. if the track exerts a normal force on the car of 2.05 multiplied by 104 N at this point, what is the mass of the car?
(b) What is the maximum speed the car can have at point B for the gravitational force to hold it on the track?