A hollow crystal is made of glass that is 3 cm thick. The ball has a radius to the outside surface of 8 cm.

What is the approximate volume of glass used to make the ball?

Use 3.14 to approximate π

hoiuu Mar 1, 2019

#1**0 **

Volume of the 8cm sphere - volume of 5 cm sphere = glass volume

volume of a sphere = 4/3 pi r^3 Get your calculations on !

= 4/3 pi (8^3 - 5^3) = 516 pi = 1620.2 cm^3

ElectricPavlov Mar 1, 2019

edited by
Guest
Mar 1, 2019

edited by Guest Mar 1, 2019

edited by Guest Mar 1, 2019

#5**0 **

No you don't......you are dealing with radii one radius is 8 the inner is 5

ElectricPavlov
Mar 1, 2019

#2**-1 **

since it is hollow, you need to take the whole volume minus the air inside

heres a diagram ish

| | | |

| | inside | |<------- outside glass

| | | |

3cm 2cm 3cm

<<---------8cm-------------->>

so, thats the ball

now we find volume

v=4/3 pi r^{2}

^{8cm= 2144.66 cm}

^{2cm=33.51cm}

^{2144.66-33.51= 2111.15cm^2}

hope that helped

-DBZ

DivideByZero Mar 1, 2019

#4

#6**-1 **

i put it in the google calc so either way it would be the same, i just messed up the formula, sorry

DivideByZero
Mar 1, 2019