Question

As a person pedals the bike, what forces oppose motion?

Answer 1

When biking on a level road, your forward force comes from pushing and pulling on the pedals to make the back tyre push backwards against the road. The two main forces that oppose your motion are aerodynamic drag (air resistance) and rolling resistance of the tyres against the road caused as the tyre is compressed.

Answer 2

As a person pedals a bike, the forces opposed to the motion are the air resistance, and the rolling resistance of the tyres.