Question

Dana plans to cover this model of a half moon completely with silver foil.



How many square centimeters of silver foil would Dana need to cover the model completely?

402.2

536.2

603.4

150.8

Answer 1

Dude, this is a homework help site, do not ask for emails :P

Answer 2

its not and ur a player

Answer 3

true @trackzz

Answer 4

well the surface area of a hemisphere is

\[SA = \frac{1}{2}(4pir^2) + \pi r^2\]

and you have a radius of 8 cm

just substitute and solve.

Answer 5

i dont know how to do that

Answer 6

cause i just see leters

Answer 7

@campbell_st

Answer 8

ok... do you have a calculator ?

Answer 9

yesss

Answer 10

ok you need to type in

\[0.5 \times 4 \times \pi \times 8^2 + \pi \times 8^2\]

that will give the answer to covering the hemisphere in foil..

Answer 11

Alrii so basically what campbell has show you is the surface are of a sphere. Any problem in which they ask for something that wraps around a specific shape involves surface are.

The surface area of a sphere is: 4 pi r^2
Where r is the radius of the sphere.

Answer 12

what is p 12.18 or 12.14

Answer 13

If you're familiar with the button pi, it is the value of 3.14.

Now for this particular question, it is a hemisphere. So half the surface are of the sphere.

1/2*(4pi r^2) = SA

Answer 14

thnks

Answer 15

@crystal1 what are you talking about>

Answer 16

you said:" what is p 12.18 or 12.14"
what do you mean?

Answer 17

my bad sorry

Answer 18

so you got the answer?

Answer 19

wait

Answer 20

my answer is 5048.1152

Answer 21

nope... thats a long way from being correct

Answer 22

did you type in the equation I gave you as its written...?

Answer 23

Shall we break it down Campbell?
I think it's the BEDMAS

Answer 24

Alright crystal, I want you to do r^2 first. Find the value of the radius squared.

Answer 25

yes i did @campbell_st

Answer 26

and tracks... I think you possible solution is missing the circular base... as the question talks about competely covering... it

Answer 27

you guys lost me now im confuse

Answer 28

ok... lets to it in little bits can you calculate

\[0.5 \times 4 \times \pi \times 8^2\]

Answer 29

Ok my bad, alrii yeah you're right. I'll leave this to Campbell. Dont wanna confuse you,

Answer 30

@crystal1 did you get an answer for the new calculation..?

Answer 31

b

Answer 32

what was the number..?

Answer 33

i dont reaally know im sorry im dumb i dont know how to start this thats why i need help

Answer 34

You're not dumb. Tell yourself you're smart. You'll get the answer. Crystal, you got this. Wake up, look at what campbell wrote for you.

Answer 35

the answer is a

Answer 36

you're not finished yet. Add the pi r^2 to what you got to get the answer

Answer 37

nope thats only the 1st part of the problem

the curved surface has an area of 402.2 cm^2

now you need to find the area of the circular base...

\[\pi \times 8^2\]

Answer 38

you need to calculate this number...

Answer 39

then the final answer will be

\[402.2 + \pi \times 8^2 = \]

Answer 40

6485.44

Answer 41

wow... nope not it

lets make it easier

what is

\[\pi \times 8^2 =\]

Answer 42

75.36

Answer 43

nope still not right...

\[\pi \times 8^2 = 201.1\]

Answer 44

how do you get thaat i tough that 8x2 its = 24

Answer 45

do you know how to square a number...

Answer 46

no

Answer 47

ok... then perhaps you need to ask you teacher... how to do the problem is you don't know the basics...

Answer 48

thnks you @campbell_st