The radius of a sphere is measured to be `(2.1+-0.5)` cm. Calculate its surface area with error limits .

Explanation

Surface area, `S=4pir^(2)=(4)((22)/(7))(2.1)^(2)`
`=55.44=55.4 cm^(2)`
Further, `(DeltaS)/(S)=2,(Deltar)/(r)` or `=DeltaS=2((Deltar)/(r))(S)`
`(2xx0.5xx55.4)/(2.1)=26.38=26.4cm^(2)`
`S=(55.4pm26.4)cm^(2)`