Question

Two measurement are as A=2.00+-0.01cm and B=1.00+-0.01cm.then [AB] is

Answer 1

answer : (2.00 ± 0.03) cm²

explanation : The measurements are as A = (2.00 ± 0.01)cm and B = (1.00 ± 0.01)cm

we have to find AB = ?

AB can be written as r ± ∆r

so, first find r i.e., r = (2.00)(1.00) cm²

= 2.00 cm²

To find ∆r, use formula, ∆r/r = ∆A/A + ∆B/B

here, r = 2.00 cm², ∆A = 0.01cm, A = 2.00cm , ∆B = 0.01 cm and B = 1.00cm

now ∆r/2 = 0.01/2 + 0.01/1

or, ∆r = 2 (0.01/2 + 0.02/2) = 0.03

so, ∆r = 0.03 cm²

hence, The appropriate value of AB = (2.00 ± 0.03) cm²