physics - friction

Question 1

what is friction?

Answer 1

friction is a force when two surfaces of an object sliding together, or trying to slide, across each other.

Question 2

frictional force can be divided into 3 parts

Answer 2

1) static friction
2) limiting friction
3) dynamic friction

Question 3

what is static friction

Answer 3

the frictional force that act when there is no relative motion, even though, a force is applied on the body

Question 4

what is limiting friction?

Answer 4

frictional forces that act on the body as it just begins to move.

Question 5

what is dynamic friction?

Answer 5

the frictional force that acts on bodies when they are in relative motion.

Question 6

fact of dynamic friction ( explaining newton’s first law)

Answer 6

dynamic friction = external friction= constant velocity

Question 7

fact of dynamic friction ( explaining newton’s 2nd law)

Answer 7

resulted force = external force - dynamic friction

Question 8

why does limiting frictional force increase

Answer 8

limiting frictional force increases when the normal reaction between the two forces increases

Question 9

methods to reduce friction

Answer 9

apply oil

apply grease

apply the bearing

Question 10

advantages of friction

Answer 10

breaks of vehicle work due to friction

objects can be pilled up without slipping

Question 11

disadvantages of friction

Answer 11

makes work tedious

reduce speed