A student collected information about air masses from the model. She learns that air masses are huge bodies of air that form over
water or land in tropical or polar regions. They may extend across
an entire continent and are relatively uniform in temperature and
moisture content. What happens as an air mass moves over any
particular area?

A The characteristic of the air mass changes along with the weather of that area.
B The characteristic of the air mass along with the
weather of that area remain the same.
C The underlying vegetation and water bodies’ characters in that area remains the same and no change occurs.
D There will be many days of drought in that area.

Acommon procedure for measuring the velocity of an airstream involves the insertion of an electrically heated wire (called a hot-wire anemometer) into the airflow, with the axis of the wire oriented perpendicular to the flow direction. the electrical energy dissipated in the wire is assumed to be transferred to the air by forced convection. hence, for a prescribed electrical power, the temperature of the wire depends on the convection coefficient, which, in turn, depends on the velocity of the air. consider a wire of length l = 20 mm and diameter d = 0.5 mm, for which a calibration of the form v = 6.25 ă— 10â’5 h2 has been determined. the velocity v and the convection coefficient h have units of m/s and w/m2 â‹… k, respectively. in an application involving air at a temperature of tâž = 25â°c, the surface temperature of the anemometer is maintained at ts = 75â°c with a voltage drop of 5 v and an electric current of 0.1 a. what is the velocity of the air?