A bicyclist is coasting down a road that is sloped downward at an angle of 8°. The bicycle and bicyclist have a total mass of 80 kg. If the bicycle wheels roll freely, without any effect from friction or air resistance slowing the motion, how fast would the bicyclist accelerate?

Answer 1

Wc = mg = 80kg * 9.8N/kg = 784N. = Weight of bicyclist and bike.

Fc = 784N. @ 8deg.
Fp = 784sin8 = 109.1N.. = Force parallel to hill.

Fn = Fp = 1o9.1N.
Fn = ma,
a = Fn / m = 109.1 / 80 = 1.36m/s^2.