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Exercise 1903Calculus › Multivariable calculus › Vector calculusM1Added 3 Nov 2026

Gauss divergence theorem for a cylinder

#divergence#cylinder#flux

Statement

Compute the outward flux of F⃗=(x,y,0)\vec F=(x,y,0) through the cylinder x2+y2≤R2x^2+y^2\le R^2, 0≤z≤h0\le z\le h.

Hint

div⁡F⃗=2\operatorname{div}\vec F=2; multiply by the volume.

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Solution

Divergence. div⁡F⃗=1+1+0=2\operatorname{div}\vec F=1+1+0=2.

Volume. πR2h\pi R^2h.

Flux. 2πR2h2\pi R^2h.

Conclusion. Flux =2πR2h=2\pi R^2h.