1.
A student performs an experiment to determine the Young's modulus of a wire, exactly 2m2\,\text{m} long, by Searle's method. In a particular reading, the student measures the extension in the length of the wire to be 0.80mm0.80\,\text{mm} with an uncertainty of ±0.05mm\pm 0.05\,\text{mm} at a load of exactly 1.0kg1.0\,\text{kg}. The student also measures the diameter of the wire to be 0.4mm0.4\,\text{mm} with an uncertainty of ±0.01mm\pm 0.01\,\text{mm}. Take g=9.8m/s2g = 9.8\,\text{m/s}^2 (exact). The Young's modulus obtained from the reading is