Question

i need help please :D

A ball has a diameter of 9 in. It consists of 2 parts. The inside is a spherical core with a diameter of 6 in. Surrounding the core is a layer of polyurethane.

What is the volume of the polyurethane?
Use 3.14 to approximate pi and express your answer in hundredths.

____in3

Answer 1

@freckles

Answer 2

@horsegirl325

Answer 3

find the volume of the whole ball
then subtract out the volume of the spherical core

Answer 4

oh okay. thanks

Answer 5

do you know the volume of a sphere?

Answer 6

no D:

Answer 7

i was thinking you were going to say yes. it is weird your homework ask you to apply the volume of a sphere without you not having it in your notes.

Answer 8

\[V=\frac{4}{3} \pi r^3\]
is the volume of a sphere
this is the formula you will use to find the volume of the whole ball
and also the formula you will use to find the volume of the spherical core
r means radius
you are given diameter
you divide diameter in half to find the length of radius

Answer 9

ohhh, okay, ill tell you what i get c:

Answer 10

684*3.14 = 2147.76 in³.

i got 2147.76

Answer 11

@freckles

Answer 12

hmm
how did you get that

Answer 13

did you find the difference yet of the two volumes ?

Answer 14

the volume of the whole sphere is 972

the volume of the inner core is 288

972π - 288π = 684π

Answer 15

@freckles

Answer 16

can i ask how you got the volume for the whole sphere ?

Answer 17

\[V_\text{ whole sphere}=\frac{4}{3} \cdot 3.14 \cdot (\frac{9}{2})^3\]
all I did is use the formula above

Answer 18

that one should equal 381.51
try the second sphere ( the inner sphere) again