The roller coaster car has a mass of 700 kg including its passenger - 14-73

14.5 Conservative Forces and Potential Energy
14.6 Conservation of Energy
14–73. The roller coaster car has a mass of 700 kg including its passenger. If it starts from the top of the hill A with a speed vA = 3 m/s, determine the minimum height h of the hill crest so that the car travels around the inside loops without leaving the track. Neglect friction, the mass of the wheels, and the size of the car. What is the normal reaction on the car when the car is at B and when it is at C? Take rB = 7.5 m and rC = 5 m.

All problems from Engineering Mechanics: Dynamics Fourteenth Edition in SI Units by R. C. Hibbeler.

[thushendranbalamuraly]

Why for roller coaster C we can't assume N =0

[be_y.o.u.r.s.e.l.f]

You are

Could you please solve this problem?👇🏻
A 3.7-kg block slides over the smooth, icy hill. The top of the hill is horizontal and h, = 79 m
higher than its base. What minimum speed must the block have at the base of the hill so that it will not fall into the pit on the far side of the hill that is h2 = 59 m above the base? The distance between the top and the far side pit is d = 38 m. The gravitational acceleration is g = 9.8 m/s2.
(43. 613988581647 m/s).

There is also a picture for this problem, but I cannot attach it.