Question

Medal + fan:
The volume of a sphere is 4,000pi m^3. What is the surface area of the sphere to the nearest square meter?
A 2,614m^2
B 3,836m^2
C 1,307m^2
D 764m^2

Answer 1

@Erak

Answer 2

So find the radius when given volume of a sphere.

V = (4/3)pi(r)^3

Answer 3

How exactly do I set this one up?

Answer 4

So you're given volume

V = (4/3)pi(r)^3
4000pi = (4/3)pi(r)^3

I would just cross out pi, as it's on both sides, so solve this for r

4000 = (4/3)(r)^3

Answer 5

When I do it I get 9.847

Answer 6

I feel like I'm not doing it correctly...

Answer 7

so divide both sides by (4/3), which basically is 4000*3/4, then cube root it

Answer 8

I got 3,000 and then 14.422

Answer 9

yeah

Answer 10

So that's your radius, put it into the SA formula

Answer 11

I got 2,461.76?

Answer 12

What if thats not one of my choices? @Erak

Answer 13

So that's probably cause you rounded somewhere. Logically, it's close enough to A that you could guess that based on what you got

Answer 14

Okay, that makes sense but i'm not sure what I did.

Answer 15

So does your calculator have an "Ans" function? Go back to getting your radius of 14.422, then do 4pi*ans^2