Question

current attempt in progress
air resistance is a nonconservative force. it always opposes the motion of an object. an airplane flies from new york to atlanta and then returns to its point of departure. the net work done by air resistance during this round trip _________.

is zero
is negative for higher speeds and positive for slower speeds
is negative
is positive
is negative for slower speeds and positive for higher speeds

Explanation:

Work done by a non - conservative force is given by $W = \vec{F}\cdot\vec{d}$, where $\vec{F}$ is the force and $\vec{d}$ is the displacement. Air resistance always opposes the motion of the airplane. When the airplane flies from New York to Atlanta, air resistance does negative work as it is opposite to the displacement. When it returns, air resistance again does negative work as it is opposite to the return - displacement. So the net work done by air resistance in the round - trip is negative.

Answer:

is negative