1. Which statement is true about friction?A. Friction causes an object to fall.
B. Friction causes a moving object to speed up.
C. Friction acts to resist the motion of an object.
D. Rougher surfaces have less friction between them.
2. A boy is playing a big toy truck with his friends. If he wants it to travel the fastest, on which surface should he roll his toy?
A. carpeted floor
B. concrete floor
C. polished floor
D. wooden floor