Two boys pull their identical sleds to the top of a hill. One boy loads his sled with bricks while the other boy does not put any extra objects in his sled. The two boys, each weighing the same, get into their sleds and have a friend start them with equal pushes down the hill. Which of the following hypotheses are the boys most likely testing?
A. The heavier the object, the more momentum it will have.
B. The force of sliding friction is greater than the force of rolling friction.
C. The size of the frictional force is determined by the types of surfaces rubbing together.
D. The faster an object is traveling, the more momentum it will have