At the end of the course, each student should be able to…
- S10: SurfInt. Compute and apply surface integrals.
S10: Surface Integrals
- The net volume of a solid with base given by the surface \(S\) and
heights given by \(f(x,y,z)\) at each point is given by the
surface integral \(\iint_S f\,d\sigma\).
- When the surface is parametrized by \(\vect r(u,v)\) with domain \(G\) in the \(uv\) plane, this integral may be computed as \(\iint_G f(\vect r(u,v))\|\vect r_u\times\vect r_v\|\,dA\).
- The orientation of \(S\) is irrelevant.
- The flux of the vector field \(\vect F\) passing through the surface
\(S\) oriented by \(\vect n\) is given by
\(\iint_S \vect F\cdot\vect n\,d\sigma\).
- When \(\vect r(u,v)\) parametrizes \(S\) with the correct orientation, then this integral may be computed as \(\iint_G \vect F(\vect r(u,v))\cdot(\vect r_u\times\vect r_v)\,dA\).
- When \(\vect r(u,v)\) parametrizes \(-S\) (with opposite orientation), then this integral may be computed as \(-\iint_G \vect F(\vect r(u,v))\cdot(\vect r_u\times\vect r_v)\,dA\).
Textbook References
- University Calculus: Early Transcendentals (3rd Ed)
- 15.6 (exercises 1-36)