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

Question

Why does the bicycle keep moving at a constant speed?

Answer options with 4 options
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 the forces acting on an object are balanced (in this case, the pedaling force and the frictional force), the object will continue to move at a constant speed according to Newton's first law of motion.