Anemometer is blowing on the back of the cup on the opposite end of the cross. Since a hollow hemisphere has a drag coefficient of .38 on the spherical side and 1.42 on the hollow side, more force is generated on the cup that is presenting its hollow side to the wind. Because of this asymmetrical force, torque is generated on the axis of the anemometer, causing it to spin. Theoretically, the speed of rotation of the anemometer should be proportional to the wind speed, because the force produced on an object is proportional to the speed of the fluid flowing
P.S.K. What Does It Mean? P.S.K. What Does It Mean? "P.S.K. What Does It Mean?" (also written as "P.S.K. (What Does It Mean?)") is a song released in 1985 by Philadelphia rapper Schoolly D on his independent label Schoolly D Records. P.S.K. is the abbreviation for Park Side Killas, a street gang with which Schoolly D was affiliated. The highly influential song is considered the first hardcore rap song and features incidents of graphic sex, gunplay, drug references and one of the first uses of the word "nigga" in a rap song (earlier uses include "Scoopy Rap" and "Family Rap" in 1979, and "New York