Suppose a parachutist is falling toward the ground, and the downward force of gravity is exactly equal to the upward force of air resistance. which statement is true?
a. velocity of parachutist must be zero
b. velocity of parachutist is not changing with time
c. the velocity of parachutist is increasing with time
d. velocity of parachutist is decreasing with time

Explanation:

When the downward force of gravity on a falling parachutist is exactly equal to the upward force of air resistance , net force on the parachutist will be zero . As a result of it , there will be no acceleration in his downward motion . In other words , his downward velocity will not be either increasing or decreasing . It will remain steady .

So option b) is correct.