Physics

# The diameter of a sphere is $4.24\ m$. Its surface area with due regard to significant figures is :

56.5 ${ m }^{ 2 }$

##### SOLUTION
$d=4.24\;m$
$SA=$ Surface area $=4\pi r^{2}=4\pi \left ( \dfrac{d}{2} \right )^{2}=\pi d^{2}$
$=\pi \left ( 4.24 \right )^{2}$
$=56.47\ m^{2}$
Since significant figure in 4.24 is 3, so we express the answer in 3 significant figures.
$SA=56.47\ m^2 \approx 56.5\ m^2$
(Rounding off to 3 significant figures - if digit to be dropped is more than 5, the preceding digit is raised by 1)

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Single Correct Medium Published on 18th 08, 2020
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