After evaluating the speed of sound u several times, a student concludes that the standard deviation s_u of her measurements is s_u = 10 m/s. When all uncertainties were truly random, she could get any desired accuracy by making adequate measurements and averaging. (i) Determine how many measurements are required to provide a final uncertainty of ±3 m/s? (ii) Determine how many for a final uncertainty of just ±0.5 m/s?