Braking Speed Answer

So, what was the cyclist's speed if his braking distance was 5 m, braking force 1,000 N, and combined mass 80 kg?

The answer:

F d = ½ m v²
1,000 × 5 = ½ × 80 × v²
5,000 = 40 × v²
125 = v²
v = 11·1 m/s

If you coped with that tricky rearrangement, you're on for a fabulous grade!