14. Which type of friction makes flying possible for birds? a. static friction b. air friction c. sliding friction d. rolling friction 15. Which type of friction affects the steel wool being rubbed on a pot? a. static friction b. air friction c. sliding friction d. rolling friction 16. Which type of friction keeps you from falling when you are standing on top of a santol tree? a. static friction b. air friction C. sliding friction d. rolling friction 17. Which type of friction makes a car move on the road? a. static friction b. air friction c. sliding friction d. rolling friction 18. Which example does not show the usefulness of friction? a. Sharpening of talibong b. Brushing your teeth. c. starting a fire. d. Putting lubricant in a sliding window. 19. What would likely happen if there is no friction? a. Cars cannot move on the road b. Birds will be able to fly c. You can remove the dirt from your teeth d. We can make a fire using mathces 20. Which activity does not reduces friction? a. Using lubricants b. Using ball bearings in rotating machines and shaft c. Polishing uneven surfaces d. Making the surface rough
