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anonymous
 5 years ago
Find the surface area
anonymous
 5 years ago
Find the surface area

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dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0hello for the first one you need to use formula for SA of sphere and then plug in the radius so what is SA of a sphere? what is the radius of our sphere?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so i have to divide 1.8 by 2

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0correct because radius is half the diameter

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0now substitute that in for r in SA formula

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0ok i am doing it right now

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i did the volume then i got 0.972pi

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0correct for volume i thought we were doing surface area

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yea but my homework say to find both of them

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0oh ok what would SA be then

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0good job for next one do the same thing except at the end we will divide by 2 because its only half a sphere

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0it shows image of half sphere with radius of 12 right? so find volume and SA using same formulas substituting 12 for r but we only want half the volume and half the SA

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i find the volume is 1152pi

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0no i get 288pi SA = 4pi*12^2 = 4pi*144 = 576pi take half of 576 288

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0ok thank here the another question: The shaded circle at right has area 40π cm2. Find the surface area of the sphere.

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0i dont understand how are the circle and sphere related?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0here the hint:The surface area of a sphere is how many times the area of a circle with the same radius?

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0ok so they share the same radius is the entire circle shaded?

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0ok thanks use area of circle formula to find radius, then plug that into SA formula A = pi*r^2 = 40pi

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i have to divide pi in both side

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i find the raidus 6.32455532

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0correct and you can round up to 160 since we rounded the radius

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Find the volume of a sphere whose surface area is 64π cm2.

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0first find radius 4pi*r^2 = 64pi

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0good now use that to find volume V = 4/3pi*r^3

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Find the surface area of a sphere whose volume is 288π cm3.

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0same thing we just did except use volume formula to find radius V = 4/3pi*r^3 = 288pi

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0what should i do with 4/3 pi?

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0well first get rid of pi by dividing pi on both sides like last time then we will divide by 4/3

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0x by 3/4 by both side

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0think of it as (288*3)/4

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0correct put that in SA formula

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0if the radius of the base of a hemisphere (which is bounded by a great circle) is r, what is the area of the great circle? What is the total surface area of the hemisphere, including the base? How do they compare?

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0you can do this one, its just using the formula for circle area and SA the radius is just r

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0ok i will but i need to leave right but i tell you when i get home

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0ok i'm back so my homewprk paper has Agreat cicrle=,Shemisphere= and SA Hemisphere=__xA of great circle

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0yes lets fill in the gaps A = area circle SA = area circle + 1/2 SA of sphere

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0the area of that is pir^2

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0we know the radius is r so that mean..

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0good SA hemishere = pir^2 +(1/2)*4pir^2 add like terms

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0good and A = pir^2 right? so SA = ___ * A

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0what the of Agreat cicrle= and Shemisphere=

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i forgot to put answer

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0A = pir^2 SA hemishere = pir^2 +(1/2)*4pir^2 add like terms

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so that is the answer or i have to solve it

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0no thats the answer, remember we dont know what r is

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0well does that sense? sub in what we know SA = 3pir^2 and A=pir^2 3pir^2 = r*pir^2 is that true?

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0ok look at it this way SA = 3pir^2 if i plug in A for pir^2 i get SA = 3A

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0oh now i got it If Jose used 4 gallons of wood sealant to cover the hemispherical ceiling of his vaction home, how many gallons of wood sealant are needed to cover the floor?

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0ok use what we just learned SA = 3A = 4 gal + gal for the floor

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0sorry i was unclear there we dont know num of gall for the floor, lets call it x

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0we know SA of top is 2*pir^2 SA = 2pir^2 = 2A

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0total = 3A A = 2 gall so total = 3*2 = 6 gallons

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i got it thank you so much

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0if i need help for my homework can u help me

dumbcow
 5 years ago
Best ResponseYou've already chosen the best response.0yeah if you post it and im on sure

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0thank again ^_^ that help me a lot from you
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