Question

What is the approximate uncertainty in the area of a circle of radius 4.5×10^4 cm? Express your answer using one significant figure.

Answer 1

Answer:

$A=6.36\times 10^5\ m^2$

Explanation:

It is given that,

Radius of the circle, $r=4.5\times 10^4\ cm=4.5\times 10^2\ m$

The area of the circle is given by :

$A=\pi r^2$

$A=\pi (4.5\times 10^2\ m)^2$

$A=636172.51\ m^2$

or

$A=6.36\times 10^5\ m^2$

As there is no uncertainty given in the radius of the circle. So, the area of the circle is $6.36\times 10^5\ m^2$. Hence, this is the required solution.