6. A rectangular plate has a length of (`21.3 \+- 0.2`) cm and a width of (`9.8 \+- 0.1`) cm. Calculate the area of the plate, including its uncertainty.


Hint
`(∆A)/A =(∆L)/L + (∆W)/W`
Answer
`(209 ± 4) cm^2`
Show Steps
Area: `A = WL = 21.3 cm times 9.8 cm = 208.74 cm^2 ≈ 209 cm^2` Uncertainty: `(∆A)/A =(∆L)/L + (∆W)/W` `(∆A) =((∆L)/L + (∆W)/W)A` `∆A = (0.2 / 21.3 + 0.1/9.8) times 208.74 cm^2 = 4.17 cm^2≈ 4 cm^2` Answer `(209 ± 4) cm^2`