- #1
mgibson
- 29
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1. The problem statement
The problem requires me to calculate the flux of F=x^2 i + z j + y k out of the closed cone, x=sqrt(y^2 + z^2) with x between 0 and 1.
I am having trouble approaching this problem because most of the problems I have done give the curve as z=f(x,y) instead of x=f(y,z) and I am therefore confused as to how to apply the below equation.
For the flux through a surface given by z=f(x,y)
Flux = int(F . dA) = int( [ F(x,y, f(x,y)) dot (-df/dx i - df/dy j + k) ]dxdy
where df/dx is the partial derivative of f with respect to x and df/dy is the partial derivative of f with respect to y.
How can I modify/apply this formula (if I even can) when given a surface as a function of x=f(y,z) as opposed to z=f(x,y) to find the flux through the horizontally opening cone?
Any help would be greatly appreciated! Thanks so much.
I tried putting f in terms of z and going that route but ran into some nasty integrals.
I tried replacing z with x and x with z (for F and f) as to simulate the same vector field and cone in a way that better applied to the given formula but once again ran into some nasty integrals.
Suggestions?
The problem requires me to calculate the flux of F=x^2 i + z j + y k out of the closed cone, x=sqrt(y^2 + z^2) with x between 0 and 1.
I am having trouble approaching this problem because most of the problems I have done give the curve as z=f(x,y) instead of x=f(y,z) and I am therefore confused as to how to apply the below equation.
Homework Equations
For the flux through a surface given by z=f(x,y)
Flux = int(F . dA) = int( [ F(x,y, f(x,y)) dot (-df/dx i - df/dy j + k) ]dxdy
where df/dx is the partial derivative of f with respect to x and df/dy is the partial derivative of f with respect to y.
How can I modify/apply this formula (if I even can) when given a surface as a function of x=f(y,z) as opposed to z=f(x,y) to find the flux through the horizontally opening cone?
Any help would be greatly appreciated! Thanks so much.
The Attempt at a Solution
I tried putting f in terms of z and going that route but ran into some nasty integrals.
I tried replacing z with x and x with z (for F and f) as to simulate the same vector field and cone in a way that better applied to the given formula but once again ran into some nasty integrals.
Suggestions?