1 Which best describes friction?
A. It is a rotating force
B. It is an opposing force
C. It is a force that pulls things towards the center
D. It is a force that pulls things away from the center
2. In which surface does an object move fast?
A. Rough
B. Rocky road
C. Smooth
D. Grassy
3. In which surface will you experience less friction?
A. Rough road
8. Rocky ground
C. Smooth floor tiles
D. Grassy soccer field
What force keeps our feet from siding when we are running or walking?
A. Inertia
B. Friction
C. Centripetal force
D. Gravitational force​