Question

Emma made a bowl in shop class.She decided to hollow out a half-sphere from a cube.
a)Determine the surface area of the bowl
b)Determine the volume of wood in the final product.

Answer 1

do you know the formula for finding the surface area of a sphere?

Answer 2

A=4πR^2

Answer 3

@nikato ^

Answer 4

yes. and you know the radius is 8. so what would be the surface area of a sphere with a radius of 8?

Answer 5

A=4πR^2
A=4 x pi x 8^2
= 804.2 cm^2

Answer 6

@nikato

Answer 7

what did you use for pi?

Answer 8

what do you mean

Answer 9

@nikato

Answer 10

what is value of pi?
this is what nikato is asking.

Answer 11

3.14

Answer 12

well, i got something close. 803.84, using 3.14 for pi.

then divide that by 2 because its only half a sphere

Answer 13

right

Answer 14

oh i used the pi-button on my calculator

Answer 15

well the calculator uses the entire pi. 3.14159....

Answer 16

but i'll just use 3.14 manually instead ...
ok 803.84 divided by 2=401.92

Answer 17

correct. so thats the surface area of the bowl

Answer 18

okay

Answer 19

how do i find the volume of wood

Answer 20

can you find the volume of the cube?

Answer 21

V=LxWxH
=20x20x20
=8000

Answer 22

correct. and can you fidn the volume of the half sphere?

Answer 23

the volume of the half-sphere is 401.92

Answer 24

oh nvm

Answer 25

thats the surface area

Answer 26

@nikato the volume of the sphere is 2143.5cm^3

Answer 27

*half-sphere

Answer 28

and then you divide that in half

Answer 29

1071.75

Answer 30

well thats the sphere.
divide that by 2 to find the volume of the hapf sphere/bowl

Answer 31

yes. i got something close to that. 1071.79 but its fine. close enought

now subtract this number from the volume of the cube,8000

Answer 32

6928.25cm3

Answer 33

correct. and thats it

Answer 34

alright thank you so much!

Answer 35

yup. no problem