Give some examples of usefulness of friction in air.
Answers
Answer:
birds fly in air., kite flying in air etc
Answer:
-The movement of wheels of vehicles on the road (Rolling friction)
=.> helping the car move
-Friction breaks between feet and the road surface helps people to stand without falling.
-People standing on escalators escalating (downhill) moving along the escalator thanks to the resting friction force.
-When screwing on a screw, if there is no friction, the screwdriver (wrench) and screw will slide on each other and cannot open the screw. (Fix: make the size of the wrench jaw fit the width of the screw)
-The rosin must be applied to the bowstring of the tweezers to increase the friction between the bow and the erhu so that when the strings are pulled, they will sound loudly. Thus friction in this case is useful. Because friction will make the erhu string vibrate more strongly