ests carried out with the tilting trains revealed that passengers feel queasy when they see through the car windows that the train is rounding a curve at high speed, yet do not feel any side force. Designers, therefore, prefer to reduce, but not eliminate, that force. For a train traveling at 100 mi/h on a curved section of track banked through an angle θ = 6o and with a rated speed of 65 mi/h, determine the required angle of tilt Φ if passengers are to feel side forces equal to 10% of their weights.