# Surface of enclosed volume

1. Homework Statement
Hi,
I have this problem:
the surfaces r=2 and 4, $\theta=$30 degrees and 50 degrees, $\phi=$20 degrees and 60 degrees identify a closed surface.
1- find the enclosed volume.
2- Find the total area of the enclosed surface. ( I think it is a typo from the teacher. It is volume not surface)

The first question is straigth forward
For the secon question I have some issues.

2. Homework Equations
Do I need to take take each element of surface (in spherical coordinates)
dS1=$$r^2$$ sin(theta) $$d\theta$$ $$d\phi$$

dS2=$$r$$*$$dr$$$$d\phi$$
dS3=$$\sin\theta$$*$$r$$$$dr$$$$d\phi$$

3. The Attempt at a Solution

integrate the according the limits and the total are should be
S= S1+S2+S3
Is my reasonnig correct?
Thank you
B
1. Homework Statement

2. Homework Equations

3. The Attempt at a Solution
1. Homework Statement

2. Homework Equations

3. The Attempt at a Solution
1. Homework Statement

2. Homework Equations

3. The Attempt at a Solution
1. Homework Statement

2. Homework Equations

3. The Attempt at a Solution

Last edited: