Question

Part A What is the area of a circle of radius 6.1×10^4cm?

Express your answer using two significant figures.
Part B
What is the approximate uncertainty in the area of a circle of radius 6.1×10^4cm?
Express your answer using one significant figure.
This is all the information given.

Answer 1

Step-by-step explanation:

It is given that,

Part A :

Radius of the circle,
`r=6.1* 10^4\ cm=6.1* 10^6\ m`

The radius of the circle is given by :

`A=\pi r^2`

Putting the value of r in above formula as :

`A=\pi (6.1* 10^6)^2`

`A=1.16* 10^(14)\ m^2`

or
`A=1.1* 10^(14)\ m^2`

Part B :

Radius of the circle,
`r=6.1* 10^4\ cm=6.1* 10^6\ m`

As there is no uncertainty in the radius of the circle, so the calculation is as same as in part A.

The radius of the circle is given by :

`A=\pi r^2`

Putting the value of r in above formula as :

`A=\pi (6.1* 10^6)^2`

`A=1.16* 10^(14)\ m^2`

or
`A=1* 10^(14)\ m^2`

Hence, this is the required solution.