calculate the absolute pressure at lusaka 1200 m above sea level where a pipe carrying water tapers from cross section of 0.3 m2 to 0.15m2 at B. At A the velocity, assumed uniform is 72 km/h and the pressure 65.60 m gauge. if the friction effects are negligible determine the pressure at B which is 6 m above the sea level of A and calculate the absolute pressure at A and B.