A pitot-tube probe is used to calculate the velocity of air at a given point. The air density is 1.3 kg/(m^3), and the deflection of mercury manometer is 1 cm. Calculate the velocity of air. Assume room temperature at 25 degrees Celsius. Calculat the air velocity. Specific gravity of mercury is 13.6, i.e. mercury density is 13.6 times the density of water.