A brass measuring tape is corrected at 20degree celcius.the value obtained when it the length of a field is measured with the rule at 50degree celcius appear to be 70.5,determine the true length of the field
brass about 20^10^-6 deltaL /L deg C
deltaL = 70.5 (50-20) (20*10^-6) = 42000*10^-6 = 0.042 meters (I assume)
70.5 - .042 = 70.458
in other words wrong by about 4 centimeters