Find the surface area and volume for each of the following...

Question

anonymous · Answer

attachment

pfenn1 · Answer

Do you know the formulas for the surface area and volume of a sphere?

anonymous · Answer

Yes, SA is $$4*pi*r ^{2}$$ and V is $$(4/3)*pi*r ^{3}$$

pfenn1 · Answer

So problem (c) is straightforward.
In (a), remember that the diameter is 2 times the radius.
in (b), you are dealing with a half sphere so you must divide the total vol and area by 2 to get your answer.
in (d) remember that you have to derive the radius from the circumference and then determine just like you did for (b)

anonymous · Answer

I got 267.95 for (a). Is that correct?

pfenn1 · Answer

I assume your answer is for the volume of (a)?

anonymous · Answer

oh yes, I forgot the SA, I get 200.96 for the surface area. Are these the correct answers?

pfenn1 · Answer

yep, depending on how you rounded

pfenn1 · Answer

The approx answers for (a) could be expressed as
SA = (4^3)pi = 64pi 
Vol = [(4^4)/3]pi = 85.33pi

anonymous · Answer

Alright, thanks, I think I can do the rest now :)

pfenn1 · Answer

great, good luck!