Question

What mass of a material with density ρ is required to make a hollow spherical shell having inner radius r1 and outer radius r2? (use any variable or symbol stated above as necessary.)?

Answer 1

Answer: $m=\frac {\rho}{\frac{4}{3} \pi( (r_2)^{3} - (r_1)^{3}) }$

It is given that:

Density of material =ρ

radius of inner spherical shell = $r_1$

radius of outer spherical shell=$r_2$

we know that the volume of sphere is $\frac{4}{3}\pi r^{3}$

Volume of the given spherical shell = $\frac{4}{3}\pi( (r_2)^{3}-(r_1)^{3})$

Then mass of the spherical shell can be calculate as:

Mass, m=density/ volume

$m=\frac {\rho}{\frac{4}{3} \pi ((r_2)^{3} - (r_1)^{3}) }$