SOLUTION: Ok, sorry but this word problem is killing me. It's not like any of the others I've done... Here it is: "It is shown in engineering that the maximum load a cylindrical column

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Ok, sorry but this word problem is killing me. It's not like any of the others I've done... Here it is: "It is shown in engineering that the maximum load a cylindrical column       Log On


   



Question 158845: Ok, sorry but this word problem is killing me. It's not like any of the others I've done... Here it is:
"It is shown in engineering that the maximum load a cylindrical column of circular cross-section can hold varies directly as the fourth power of the diameter and inversely as the square of the height. If a column 16 feet high and 4 feet in diameter will support a load of 10 tons, how great a load will be supported by a column 20 feet high and 6 feet in diameter?"
Thanks!
Josh

Found 3 solutions by scott8148, stanbon, Earlsdon:
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
L=kd^4/h^2 __ 10=k*4^4/16^2 __ 10=k

L=10*6^4/20^2 __ L=32.4

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
It is shown in engineering that the maximum load a cylindrical column of circular cross-section can hold varies directly as the fourth power of the diameter and inversely as the square of the height.
load = k * d^4/h^2
---------------
If a column 16 feet high and 4 feet in diameter will support a load of 10 tons,
Find "k":
10 = k * 4^4/16^2
10 = k * 1
k = 10
--------------
Equation now that we know k = 10:
load = 10 * d^4/h^2
--------------
how great a load will be supported by a column 20 feet high and 6 feet in diameter?
load = 10 * 6^4/20^2
load = 32.4 tons
===========================
Cheers,
Stan H.

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
First, write the equation of variation:
L+=+k%2Ad%5E4%2Fh%5E2 Where: L = load, d = diameter, h = height, and k = the constant of variation.
You need to find the value of k first, so substitute the given values of L (10 tons), d (4 feet), and h (16 feet).
10+=+k%284%5E4%29%2F16%5E2
10+=+256k%2F256
k+=+10
Now you can answer the question:
L+=+10%286%5E4%29%2F20%5E2
L+=+10%281296%29%2F400
L+=+32.4tons.