Molten aluminum is passed through a horizontal filter bed of ceramic spheres in order to remove drossy oxides from the aluminum. the filter bed comprises two different packings arranged in series. the first packing captures large drossy particles, and the second packing captures the smaller drossy particles. given 퐿퐿퐴퐴=0.7 퐿퐿퐵퐵,휀휀퐴퐴=휀휀퐵퐵,퐷퐷퐴퐴=4 퐷퐷퐵퐵, compute the ratio of the pressure drop through a to the pressure drop through b for a) very low reynolds numbers, and b) very high reynolds numbers. (4 points)

Two identical 82 mg dust particles very far apart (pee 0) are moving directly toward each other at a speed of 3698 m/s. the charge on each is-719 ? c. determine how close they will get to each other. let k = 9x109 n-m2/c2 & ignore gravity.

Next a skier is pulled by a tow rope up a frictionless ski slope that makes an angle of 15 with the horizontal. the rope moves parallel to the slope with a constant speed of 0.69 m/s. the force of the rope does 800 3 of work on the skier as the skier moves a distance of 8.4 m up the incline. (a) if the rope moved with a constant speed of 2.2 m/s how much work would the force of the rope do on the skier as the skler moved a distance of 8.4 m up the incline? at what rate is the force of the rope doing work on the skier when the rope moves with a speed of (b) 0.69 m/s and (c) 2.2 m/s?

With the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 1.90