Question

An wooden toy is made by scooping out a hemisphere of same radius from each end of a solid cylinder. If the height of the cylinder is 10 cm, and its base is of radius 3.5 cm, find the volume of wood in the toy. (Use π = 22/7).

Answer 1

Volume of wood in the toy = Volume of cylinder − 2(Volume of hemisphere)
$$\begin{gathered} =\mathrm{\pi }{r}^{2}h-2\times \frac{2}{3}\mathrm{\pi }{r}^3 \\ =\frac{22}{7}\times {\left(3.5\right)}^2\times 10-2\times \frac{2}{3}\times \frac{22}{7}\times {\left(3.5\right)}^3 \\ =385-179.67 \\ =205.33{\mathrm{cm}}^3 \end{gathered}$$