I don't understand this problem -- Surface area of a section of a solid sphere

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SUMMARY

The discussion revolves around calculating the surface area of a section of a solid sphere, specifically addressing the confusion regarding the inclusion of newly created faces from the cut. Participants emphasize the importance of using the formula for the surface area of a sphere, which is 4πr², and clarifying that the problem requires accounting for both the curved surface area and the flat faces resulting from the cut. The consensus is that the total surface area includes the original spherical surface area plus the additional areas from the cut, leading to a comprehensive understanding of the problem.

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samy4408
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Homework Statement
...
Relevant Equations
...
Sorry i don't understand English very well , if someone want to explain to me this problem?
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What part is giving you difficulty?
Try your best to explain what you think it's asking for. We'll see of we can set you straight.
 
samy4408 said:
Homework Statement:: ...
Relevant Equations:: ...

Sorry i don't understand English very well , if someone want to explain to me this problem?
View attachment 297876
Ordinarily I would delete a post like this, as there is no work shown, but today is your lucky day.
Do you know a formula for the surface area of a sphere whose radius is given?
Can you determine what fraction of a sphere is shown in the picture?
 
The problem is asking you to calculate the surface of a sphere that has been cut as shown.
Can you see it tridimensional in your head?
 
Mark44 said:
Ordinarily I would delete a post like this, as there is no work shown, but today is your lucky day.
Do you know a formula for the surface area of a sphere whose radius is given?
Can you determine what fraction of a sphere is shown in the picture?
I do know the formula for the surface area of a sphere , the problem is what they are asking for ,
is it the surface of the sphere that is shown ? is it 1/8 of the total surface of the sphere ?
 
samy4408 said:
is it 1/8 of the total surface of the sphere ?
yes
 
phinds said:
yes
No. You also have to add on the new faces from the cut.
 
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phinds said:
yes
So it is 2*pi
 
caz said:
No. You have to add on the new faces from the cut.
Ah. You are right of course. I missed that they want ALL of the surface area. Still a trivial problem.
 
  • #10
samy4408 said:
So it is 2*pi
That's just the surface area of the part of the sphere. The problem is asking for the area of the partial sphere surface, plus the three other sides.
 
  • #11
caz said:
No. You also have to add on the new faces from the cut.
It says a "solid sphere", so this is correct, IMO. If it was just a spherical surface that was cut, it would be different.
 
  • #12
Well boo. You guys moved on while I was busy rendering a visual aid.

1646420491341.png
 
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