# Problem: (a) While a parachutist is falling toward the ground, the downward force of gravity is exactly equal to the upward force of air resistance. Describe how/if the velocity of the parachutist changes- and explain your answer. (b) According to the universal law of gravitation, the force of the Earth pulling on the Moon is exactly the same as the force of the Moon pulling on the Earth. Explain why it has a much larger effect on the Moon than on the Earth.

###### FREE Expert Solution

In this problem, we'll consider Newton's second law of motion:

$\overline{){\mathbf{\Sigma }}{\mathbf{F}}{\mathbf{=}}{\mathbf{m}}{\mathbf{a}}}$

(a)

The force of gravity is equal to the upward force of the air resistance.

Therefore, ΣF = 0 on the parachutist.

Using Newton's second law of motion:

Fnet = ma

88% (390 ratings) ###### Problem Details

(a) While a parachutist is falling toward the ground, the downward force of gravity is exactly equal to the upward force of air resistance. Describe how/if the velocity of the parachutist changes- and explain your answer.

(b) According to the universal law of gravitation, the force of the Earth pulling on the Moon is exactly the same as the force of the Moon pulling on the Earth. Explain why it has a much larger effect on the Moon than on the Earth.