need help engineering dynamic review question

Review The roller coaster car has a mass of 850 kg, including its Part A passenger. It is released from rest at the top of the hill A. Neglect friction, the mass of the wheels, and the size of the car. Take he = 15 m , pg = 7.5 m , ho = 12 m , and Determine the minimum height h of the hill crest so that the car travels around both inside the loops without leaving the track. pc = 6 m . (Figure 1) Express your answer to three significant figures and include the appropriate units. FOE ? h= 17.73 m Submit Previous Answers Request Answer * Incorrect; Try Again; 5 attempts remaining Part B What is the normal reaction on the car when the it is at B? Express your answer to three significant figures and include the appropriate units. NB = ON Submit Previous Answers Figure Correct Part C What is the normal reaction on the car when the it is at C'? Express your answer to three significant figures and include the appropriate units. HA Nc= Value Units Submit