Solve the all parts of given question:
Question: Consider a train that rounds a curve with a radius of 540m at a speed of 160 km/h (approximately 100 mi/h).
Part A: Calculate the friction force needed on a train passenger of mass 70kg if the track is not banked and the train does not tilt.
Part B: Calculate the friction force on the passenger if the train tilts at an angle of 8.0 degree toward the center of the curve.
Please show all intermediate steps and formulas.