Vector Calculus Stokes Theorem?

2009-08-31 10:22 pm
Evaluate the line integral (double integral) over domain S of (Curl of F).dS, where S is the portion of the surface of sphere defined by x^2+y^2+z^2=1, and x+y+z>=1, and where F=r x (ihat+jhat+khat), and r=xihat+yjhat+zkhat.

thanks

回答 (2)

2009-08-31 10:58 pm
✔ 最佳答案
x² + y² + z² = 1

r² = 1

F = r x {i,j,k} = {x,y,z} x {i,j,k} = {y-z , z-x , x-y}

stokes theorem,

∮ F • dr = ∫ ∫ (∇ x F) • dS

where ∇ x F = {∂/∂x , ∂/∂y , ∂/∂z} x {y-z , z-x , x-y}

∇ x F = 2{-1,-1,-1}

∮ F • dr = ∫ ∫ (∇ x F) • dS = 2 ∫ ∫ {-1,-1,-1} • dS

∮ F • dr = -2 (Area of sphere) = -2(4πr²) = -2(4π)(1)

∮ F • dr = -8π
2015-12-02 5:36 am
this is incorrect.


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