Question

describe friction as a force that opposes a motion

Answer 1

ranscript of Friction: A Force That Opposes Motion. Friction depends on the force pushing the surfaces together. Friction also depends on the materials that make up the surfaces. As the force increases, the amount of friction increases.

Answer 2

here is your answer.
riction always acts in the opposite direction to movement, i.e. it opposes the motion of an object. Air resistance is a frictional force which opposes motionthrough air. 
hope it helped..