Question

Friction ______.

a) is a force which works in the opposite direction of motion.
b) was first proposed by Sir Isaac Newton.
c) is the reason work output is always greater than work input.
d) works in the same direction as motion.

Answer 1

Friction is a resistive force that opposes motion, working in the opposite direction of an object's relative motion.

Step-by-step explanation:

The student has asked which statement correctly describes friction. The correct answer is (a) Friction is a force which works in the opposite direction of motion. Friction is a resistive force that opposes the relative motion or the attempt at motion between systems in contact. For example, when a man pushes a box across a floor with a force of +50 N and the box moves at constant velocity, the force of friction acting on the box must be -50 N to make the net force zero, adhering to Newton's first law of motion.