This is the boss. No calculator — $g$ rounds to 10 and every number is chosen to fit in your head, the way a well-set final always is. One ride, worked line by line, and every answer feeds the next: write them down as you go.

The whole chapter rides along — energy banked by height, cashed as speed, taxed by the brakes, and re-banked by the winch against the clock. 5★ under par here is the chapter crown. Enjoy the drop.