Setting up limits for a triple integral in cylindrical coordinates

Join the discussion
Registration is free. Start your own thread to ask a follow-up.
2 replies · 2K views · last reply
norbellys
Messages
5
Reaction score
1
1. Homework Statement
I am trying to solve a triple integral using cylindrical coordinates. This is what I have to far . But I think I have choosen the limits wrong.

Homework Equations

The Attempt at a Solution


Handwritten notes on lined paper: a triple integral setup in Cartesian form with limits from -R to R, then cylindrical coordinate substitutions x = r cos θ, y = r sin θ, z = z, and rewritten limits, followed by a re-expressed integral over θ from 0 to 2π, r from 0 to R, with integrand r^2 sqrt(R^2 - r^2).
[/B]
 
Physics news on Phys.org
norbellys said:
1. Homework Statement
I am trying to solve a triple integral using cylindrical coordinates. This is what I have to far . But I think I have choosen the limits wrong.

Homework Equations

The Attempt at a Solution


Handwritten notes on lined paper: a triple integral setup from R to -R, with cylindrical coordinate substitutions x = r cos θ, y = r sin θ, z = z, and the converted limits, followed by the transformed integral from 0 to 2π, 0 to R, and 0 to sqrt(R^2 - r^2) with integrand r^2.
[/B]

Assuming your first line is correct, your change to cylindrical coordinates is almost correct. The only change I see you need is to remember that the element of volume in cylindrical coordinates is ##r~dz~ dr~ d\theta##. You forgot the ##r##.
 
LCKurtz said:
Assuming your first line is correct, your change to cylindrical coordinates is almost correct. The only change I see you need is to remember that the element of volume in cylindrical coordinates is ##r~dz~ dr~ d\theta##. You forgot the ##r##.
yes that was what I was missing !