Question:
Find the volume of a sphere whose diameter is:
(i) 14 cm
(ii) 3.5 dm
(iii) 2.1 m
Solution:
(i) Diameter = 14 cm, Radius(r) = 14/2 = 7 cm
Therefore volume $=4 / 3 \pi r^{3}$
$=4 / 3 \times 22 / 7 \times(7)^{3}=1437.33 \mathrm{~cm}^{3}$
(ii) Diameter = 3.5 dm, Radius (r) = 3.52 = 1.75 dm
Therefore volume $=4 / 3 \pi r^{3}$
$=4 / 3 \times 22 / 7 \times(1.75)^{3}$
$=22.46 \mathrm{dm}^{3}$
(iii) Diameter = 2.1m, Radius(r) = 2.1/2 = 1.05 m
Therefore volume $=4 / 3 \pi r^{3}$
$=4 / 3 \times 22 / 7 \times(1.05)^{3}=4.851 \mathrm{~m}^{3}$