The metric unit of force is Newton or N. The Newton unit is also equal
to kilogram per meter per second squared. The Newton name came from the late
physicist Isaac Newton. It is also based on the second law of motion.
Mass and velocity are the two terms which affect momentum of a bicycle going hill down.
Explanation:
As we know that Momentum describes the motion of an object. It is the combination of the objects mass and velocity.
So, obviously with no doubt mass and velocity are the two terms which affect momentum.
Momentum(p) = Mass(m) * Velocity(v)
The momentum also depends upon the mass and speed of the object.
More the mass of the object more is the momentum.
Depending upon the gravity and bicycle's motion speed momentum varies.
Bicycle moves faster the down hill if it moves with some speed as it has lesser mass the momentum also will be less.