A pilot records the atmospheric pressure outside its plane as 63cm of Hg while a ground observer records a reading of 75cm of Hg for the atmospheric pressure on the ground. Assuming that the density of the atmosphere is constant, calculate the height of the plane above the ground. (Relative density of Hg = 13.0 and that of air = 0.00013)

A thermometer with an arbitrary scale S, of equal division registers -30^oS at the ice point and +90^oS at the steam point. Calculate the Celsius temperature corresponding to 60^oS

A brass rod is 2m long at a certain temperature. What is the length for a temperature rise of 100K, if the expansivity of brass is 18 x 10^-6K^-1?