JAMB - Mathematics (1981 - No. 31)
The area of a circular plate is one-sixteenth the surface area of a ball of a ball, If the area of the plate is given as P cm2, then the radius of the ball is
\(\frac{2P}{\pi}\)
\(\frac{P}{\sqrt{\pi}}\)
\(\frac{P}{\sqrt{2\pi}}\)
2\(\frac{P}{\pi}\)
Explicació
Surface area of a sphere = 4\(\pi\)r2
\(\frac{1}{16}\) of 4\(\pi\)r2
= \(\frac{\pi r^2}{4}\)
P = \(\frac{\pi r^2}{4}\)
r = 2\(\frac{P}{\pi}\)
\(\frac{1}{16}\) of 4\(\pi\)r2
= \(\frac{\pi r^2}{4}\)
P = \(\frac{\pi r^2}{4}\)
r = 2\(\frac{P}{\pi}\)