You measure two quantities as A = 1.0 m +-0.2 m, B = 2.0 m +- 0.2 m . We should report correct value for sqrt(AB) as

You measure two quantities as A = 1.0 m +-0.2 m, B = 2.0 m +- 0.2 m .

1.	You measure two quantities as A = 1.0 m +-0.2 m, B = 2.0 m +- 0.2 m . We should report correct value for sqrt(AB) as
Answer» `1.4 m+-0.04 m` `1.41m +-0.2 m` `1.4m+-0.2 m` `1.4m+-0.2 m` SOLUTION :Given `A=(1+-0.2) m, B=(2+-0.2)m` Let `Y= sqrt(AB)= sqrt((1.0)(2.0))=1.414 m` ROUNDING off to two significant digit Y=1.4 m `(DeltaY)/(Y)=(1)/(2)[(DELTAA)/(A)+(DeltaB)/(B)]=(1)/(2)[(0.2)/(1.0)+(0.2)/(2.0)]=(0.6)/(2xx2.0)` `DeltaY=(0.6Y)/(2xx2.0)=(0.61xx1.4)/(2xx2.0)=0.212` Rounding off to one significant digit`DeltaY=0.2 m` Thus `sqrt(AB)=r+-Deltar=1.4+-0.2 m`