A child pedals a bicycle along a road at a constant speed.

Question

Why does the bicycle keep moving at a constant speed?
A. The net force on the bicycle is zero.
B. The force of her pedaling is stronger than Inertia.
C. The force of friction is larger than the force of gravity.
D. The force of her pedaling is stronger than the force of friction.

Answer 1

The correct answer is:

A. The net force on the bicycle is zero.

When an object is moving at a constant speed, it means that the forces acting on it are balanced, leading to a net force of zero. In the case of the child pedaling the bicycle, the force produced by pedaling is balanced by the forces of friction and air resistance, allowing the bicycle to maintain a constant speed.