120(4000/4002.6723)^2 = 119.84 lbs

b) 119.95 = 120(4000/x)^2, and (4000/x)^2 = .9995833…, or

4000/x = .9997915, and x = 4000.833594, so h = 4401.3 feet

The equation (looks kinda wrong to me; are you sure you typed it in right?):

W(h) = m(4000/4000 + h)^2

First of all, we can simplify this! Notice something funny? What is 4000/4000? 1! So:

W(h) = m(1 + h)^2

Whew! Easier to deal with, no?

Next you need to calculate what m is:

W(h) = m(1 + h)^2

120 = m(1 + 0)^2

120 = m(1)^2

120 = m(1)

120/1 = m

120 = m

Whaaaat?! Lol, ok. You know Amy weighs 120 lbs at sea level right? Well, what is sea level in terms of height? 0! Why? Because the other heights are all above sea level.

Now that we know m (120), let’s proceed:

a) W(h) = m(1 + h)^2 Here you need to calculate W(h):

W(h) = 120(1 + 14,110)^2

W(h) = 120(14,111)^2

I don’t have a calculator, so I’ll walk you through it.

First, do 14,111^2. Then multiply your answer by 120. That is Amy’s weight (in lbs) at 14,110 ft. above sea level!

b) W(h) = m(1 + h)^2 Here you need to calculate h:

119.95 = 120(1 + h)^2

119.95/120 = (1 + h)^2

No calculator! Sorry! But once you divide 119.95 by 120, take the square root of that answer, since it will help get rid of the exponent on the other side:

Answer = (1 + h)

Then simply subract 1 from your answer to get h:

Answer – 1 = h

And there you go! Piece of cake, no?

Hope this helps 🙂