Paper 2 · Units and Measurement
A rectangular piece of paper has length 297±1 mm and width 152±1 mm. Using ΔA/A = ΔL/L + ΔW/W, calculate the fractional uncertainty in its area.
Model answer
0.00995
Also accepted: 0.01, 1%, 0,00995
Explanation: ΔA/A = ΔL/L + ΔW/W = 1/297 + 1/152 ≈ 0.00337 + 0.00658 ≈ 0.00995, about 1%.
Derived from ZIMSEC Physics Paper 2, June 2003, Q1