18. is two surfaces that are sliding or trying to slide across each other. a. Gravity b. Friction C. Force d. Matter
19. is a kind of friction occurs when a ball or cylinder occurs. a. Fluid b. Rolling C. Static d. Sliding
20. a. Fluid is a kind of friction that affecting water from water friction. b. Rolling C. Static d. Sliding
Answers & Comments
Answer:
18. is two surfaces that are sliding or trying to slide across each other
19. is a kind of friction occurs when a ball or cylinder occurs.
20. is a kind of friction that affecting water from water friction.