A3-ft-diameter duct is used to carry ventilating air into a vehicular tunnel at a rate of 9000 ft3/min. tests show that the pressure drop is 1.5 in. of water per 1500 ft of duct. what is the value of the friction factor for this duct and the approximate size of the equivalent roughness of the surface of the duct?

Which sound characteristic is not affected by the relative motion of an object

Question 1 (5 pts): what is the maximum distance for which you can you resolve the two individual headlights of an on-coming truck as two separate lights rather than one if the headlights are separated by 2.00 m and your eye has a diameter of 1.00 centimeter? assume a wavelength of 500 nm.

Global warming will produce rising sea levels partly due to melting ice caps but also due to the expansion of water as average ocean temperatures rise. to get some idea of the size of this effect, calculate the change in length of a column of water 1.00 km high for a temperature increase of 1.00ºc. note that this calculation is only approximate because ocean warming is not uniform with depth. (answer in ×10^{-3} −3 m)