1. Imagine you are sitting in the airplane taking off from JFK. You are watching a TV monitor which shows outside temperature and plane's altitude. You notice that the airplane flies into the base of a fair-weather cumulus cloud when the altitude is 1000 m and the outside temperature is 15 oC. Estimate the relative humidity outside JFK airport at the time of the takeoff. (Hint: assume that eddies that form the cumulus clouds originate near the surface and ascend dry-adiabatically).

2. Estimate the air pressure at the cloud base from the problem 1 assuming isothermal atmosphere with the average temperature between the cloud base and the surface. (Hint: use the equation of state and integrate vertically the hydrostatic equation.)