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
Does Anybody Really Know What Time It Is? Does Anybody Really Know What Time It Is? "Does Anybody Really Know What Time It Is?" is a song by the rock band Chicago. It was included on their 1969 debut album "Chicago Transit Authority" and released as a single in 1970. The song was written and sung by Robert Lamm. The song was not released as a single until two tracks from the band's second album, "Make Me Smile" and "25 or 6 to 4", had become hits. It became the band's third straight Top 10 single, peaking at in the U.S. and No. 2 in Canada. Because the