An inquisitive physics student, wishing to combine pleasure with scientific inquiry, rides on a rollercoaster sitting on a bathroom scale. (Do not try this yourself on a rollercoaster that forbids loose heavy packages.) The bottom of the seat in the rollercoaster car is in a plane parallel to the track. The seat has a perpendicular back and a seat belt that fits around the student's chest in a plane parallel to the bottom of the seat.
The student lifts his feet from the floor, so that the scale reads his weight, 150 lb, when the car is horizontal. At one point during the ride, the car zooms with negligible friction down a straight slope inclined at 22.0° below the horizontal. What does the scale read at that point?