SOLUTION: The lifting force, F, exerted on an airplane wing varies jointly as the area, A, of the wing's surface and the square of the plane's velocity, v. The lift of a wing with an area o

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Question 1050506: The lifting force, F, exerted on an airplane wing varies jointly as the area, A, of the wing's surface and the square of the plane's velocity, v. The lift of a wing with an area of 210 square feet is 17,300 pounds when the plane is going 80 miles per hour. Find the lifting force on the wing if the plane speeds up to 170 miles per hour.
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
formula to use is:

f = k * a * v^2

f is the lifting force.
k is the constant of variation.
a is the area of the wing's surface.
v is the velocity of the plane.

you are given that, when f = 17300, a = 210 and v = 80.

the formula becomes 17300 = k * 210 * 80^2

solve for k to get k = 17300 / (210 * 80^2) = .0128720238.

now that you know k, you can solve the problem.

the formula is f = k * a * v^2

when f = .0128720238 and a = 210 and v^2 = 170^2, the formula becomes:

f = .0128720238 * 210 * 170^2.

solve for f to get f = 78120.3125

here's a tutorial on how to solve joint variation type problems.

http://www.mesacc.edu/~scotz47781/mat120/notes/variation/joint/joint.html