Question

why is friction called a opposite force

Answer 1

Friction is a resistive force.. it works against or in an opposite direction of the motion of the body on which it is acting upon,along the surface,in a contact. Therefore,if book is pushed over a rough surface towards the right....The force of friction works towards the left side..Remember... Friction can never be a force working with that if any other force...It always opposes the other motion on the floor...Thus it is always an opposite force...↗↗
Hope this answer helps....