Question

debeat on topic "is friction must " i need points for against

Answer 1

only due to friction... the brakes are applied to a vehicle and , then.. a vehicle can stop

Answer 2

Honestly, friction IS a must (undebatably), but here are few points for against:
1. Friction opposes motion. It makes it necessary to apply force on a body to keep it moving.
2.Friction generates heat in moving machine parts and results in wear and tear.
3.In machines, most of the energy dissipation takes place due to friction, hence reducing its efficiency. (work input > useful work done by machine)