Liquid is incompressible, so will carry the force applied at one end of the brake line through to the brake pad. At the same time the brake line maybe flexible.
It is not useful because if the liquid run out the car can't stop but if you use air than it is useful as when the air runs out there automatically comes more
Brakes are meant to have a lot of friction and it's useful.
Brakes, and Shoes
it is useful as because of the interlocking between irregularities present in the tyres and the road it stops the car
Wooden match and car brakes
The brakes! And the tires (no friction = no traction).
It is not useful at all for that. I use a proprietary brake cleaner from the auto store .
It is helpful for when you walk .
by turning it on :)
because it have sound energy
The friction is useful on a bike when you push it.
The liquid is called brake fluid. Sometimes it is called brake and clutch fluid. Both are the same.