# Homework Help: Air resistance on a falling person

1. Jun 9, 2007

### garagelu

If we model the air resistance on a falling person as being proportional to the square of that person's speed, in certain circumstances the proportionality constant between the air resistance and the square of the speed is equal to 0.100 kg/m.

Part A What would be the terminal velocity of a 75.0 kg person?

Part B What would be the air resistance when the person's speed is half the terminal velocity?

I think the wording of the questions is confusing me. Can someone help set this problem up?

2. Jun 9, 2007

### CaptainZappo

The problem is simply telling you that the force of the air resistance is equal to 0.100(v^2). You should check this by doing a dimensional analysis (the units of the force should be Newtons).

3. Jun 10, 2007

### esalihm

the terminal velocity occurs when the forces on the person add up to zero (vector addition)

try doing a FBD and equating the forces to each other
then solve for v

for part B, just plug in the value u found