Question

Find the volume and surface ara of a sphere whose radius is :

(i) 3.5 cm (ii) 4.2 cm (iii) 5 m

Answer 1

ANSWER:
(i) Radius of the sphere = 3.5 cm
Now, volume = $\frac{4}{3}\pi r^3$
=4/3×22/7×3.5×3.5×3.5=179.67 cm3
∴ Surface area = $4\pi r^2$
=4×22/7×3.5×3.5=154 cm2
(ii) Radius of the sphere=4.2 cm
Now, volume = $\frac{4}{3}\pi r^3$
=4/3×22/7×4.2×4.2×4.2=310.46 cm3
∴ Surface area = $4\pi r^2$
=4×22/7×4.2×4.2=221.76 cm2
(iii) Radius of sphere=5 m
Now, volume =$\frac{4}{3}\pi r^3$
=4/3×22/7×53=523.81 cm3
∴ Surface area = $4\pi r^2$
=4×22/7×52= 314.29 cm2