The volume of the shell and its interior is
v = 4/3 πr^3
= 4/3 π * 2^3
= 33.510 cm^3
That means that the mass (volume*density) is
m = 33.510cm^3 * 0.5g/cm^3 = 16.755g
So, if the interior radius of the shell is r, then the volume of the actual shell material is
v = 4/3 π(2^3-r^3) = 33.510-4.189r^3
So, since volume = mass/density, (using the actual density of Al),
33.510-4.189r^3 = 16.755/2.7
r = 1.868
So, the thickness is 0.132 cm
Aluminum floater: A spherical shell with an outer radius R=2 cm is made of aluminum (mass density of Al is 2.7 g/cm3). How thick is the shell if the average density of the spherical object is exactly 0.5 g/cm3 ? Assume there is a vacuum in the hollow interior of the shell.
Would be awesome if someone could get me going on this or have guided steps how to solve. my brain doesnt want to function and im stuck. THANKS
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