A hollow spherical shell is made of a metal of density 2.5 g/$$cm^{3}$$. If the external and the internal radii of the given sphere are 35 cm and 14 cm, respectively, find the mass of the shell.[Use $$\pi = \frac{22}{7}$$]

If the external and the internal radii of the given sphere are 35 cm and 14 cm, respectively

the volume of the spherical shell = $$\frac{4}{3}\times\ \pi\ \times\ \left[\left(external\ radii\right)^3-\left(internal\ radii\right)^3\right]$$

= $$\frac{4}{3}\times\ \frac{22}{7}\ \times\ \left[\left(35\right)^3-\left(14\right)^3\right]$$

= $$\frac{88}{21}\ \times\ \left[42875-2744\right]$$

= $$\frac{88}{21}\ \times40131$$

= $$88\times1911$$

= 168168 $$cm^3$$

As we know that the mass of a shell = density $$\times$$ volume

= $$2.5\times\ 168168$$

= 420420 g