【单选题】A micrometer with ∆ ins =0.004mm is used to measure the diameter of a steel ball only once, what is the absolute uncertainty of the measured result?
【简答题】A mercury manometer at 21.1(°C) reads 26.5 (cm). The local acceleration of gravity is 9.79(m)/(s)2. The barometer (brass scale) also at 21.1(°C) reads 74.19 (cm) of mercury . What is the absolute pres...