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
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
No you don't......you are dealing with radii one radius is 8 the inner is 5
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 r2
8cm= 2144.66 cm
2cm=33.51cm
2144.66-33.51= 2111.15cm^2
hope that helped
-DBZ
i put it in the google calc so either way it would be the same, i just messed up the formula, sorry