A sky diver of mass 80.9 kg (including outfit and equipment) floats down suspended from her parachute, having reached terminal speed. The drag coefficient is 0.575, and the area of her parachute is 20.27 m2. The density of air is 1.14 kg/m3. What is the air's drag force on her? (upward is positive, downward negative)

I am only going to do this one. I have already taken this course. It is your turn.

This problem is trivial since there is no acceleration.
The weight m g = the air drag force
= 80.9*9.81 = 794 Newtons

However much more interesting would be the speed which you could get as follows:
Fup = .5 rho v^2 A Cd
Fdown = -m g
sum = m a = 0

.5 (1.14) v^2 (20.27)(.575) = 80.9 (9.81)

why you don't help me for anothers. if ý don't pass this lesson my schollarship is going to cut... please if you can do anotherss for me

Try yourself, post work.

is problem ý don't know any idea for physics... anyy.. because of these ý cant pass thes exam since 2 years... and knýw the teacheser give us the homeworks and ýf ý did this homeworks ý can possiblity to pass 30% pleasee.

I do not like to be mean but it is not my task to just do your home work for you. If you get stuck that is what we are here for. However we do not just plow ahead and do all the problems. It would be great practice for me but I have been doing these since 1954. You are the one who is supposed to be learning and you would not learn much by simply copying my solutions. Try a problem.

ý think is not too much hard for you to do anothers.. if you want to help me ok. if you don't is your opinion:S:S

To calculate the air's drag force on the skydiver, we can use the formula:

Drag Force (F) = (1/2) * Drag Coefficient (C) * Air Density (ρ) * Velocity^2 * Area

Let's break down the given information:

Mass of the skydiver (m) = 80.9 kg
Drag Coefficient (C) = 0.575
Area of the parachute (A) = 20.27 m^2
Density of air (ρ) = 1.14 kg/m^3

First, we need to determine the velocity of the skydiver, which is the terminal speed, where the drag force equals the gravitational force pulling the skydiver down:

Gravitational force = Mass * Gravity

The acceleration due to gravity (g) is approximately 9.8 m/s^2.

Gravitational force = 80.9 kg * 9.8 m/s^2

Next, we can use this gravitational force value to find the velocity at terminal speed:

Gravitational force = Drag Force

80.9 kg * 9.8 m/s^2 = (1/2) * 0.575 * 1.14 kg/m^3 * Velocity^2 * 20.27 m^2

Solving for the velocity (V^2):

Velocity^2 = (2 * 80.9 kg * 9.8 m/s^2) / (0.575 * 1.14 kg/m^3 * 20.27 m^2)

Now, let's calculate the velocity:

Velocity = Square root of [(2 * 80.9 kg * 9.8 m/s^2) / (0.575 * 1.14 kg/m^3 * 20.27 m^2)]

After calculating the velocity, we can substitute this value back into the first formula to find the drag force:

Drag Force (F) = (1/2) * Drag Coefficient (C) * Air Density (ρ) * Velocity^2 * Area

Now, you can substitute the known values into the formula to find the air's drag force on the skydiver.