SOLUTION: The force of the wind blowing on a vertical surface varies jointly as the area of the surface and the square of the velocity. If a wind blowing at 40 km/h exerts a force of 50 N o

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: The force of the wind blowing on a vertical surface varies jointly as the area of the surface and the square of the velocity. If a wind blowing at 40 km/h exerts a force of 50 N o      Log On


   

Question 1130887: The force of the wind blowing on a vertical surface varies jointly as the area of the surface
and the square of the velocity. If a wind blowing at 40 km/h exerts a force of 50 N on a
surface of 500 m2, how much force will a wind of 80 km/h place on a surface of 2 m2?
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
F, force
A, area
v, velocity
k, variation constant


F=kAv%5E2

-
k=F%2F%28Av%5E2%29

k=50%2F%28500%2A40%5E2%29
k=1%2F%2810%2A1600%29
k=1%2F16000
-
cross%28F=%281%2F40%29%28Av%29%29

Answer by ikleyn(52813) About Me  (Show Source):
You can put this solution on YOUR website!
.


            The solution by @josgarithmetic is   T O T A L L Y   W R O N G   and does not follow the problem condition.

            So I came to bring a correct solution,  which is below. 


F, force
A, area
v, velocity
k, variation constant



F = kAv%5E2

k = F%2FAv%5E2

k = 50%2F%28500%2A40%5E2%29

k = 1%2F%2810%2A40%5E2%29

k = 1%2F16000

-

F = %281%2F16000%29%28Av%5E2%29%29 = %281%2F16000%29%2A%282%2A80%5E2%29 = 0.8 N.     ANSWER

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By the way, are you familiar with the conception commonly accepted between educated and civilized people to thank after getting help ?