The purpose of this problem is to give you a feel for the magnitude of reynolds number appropriate to real airplanes in actual flight. a. consider a dc-3 s. the wing root chord length (distance from the front to the back of the wing where the wing joins the fuselage) is 14.25 ft. consider the dc-3 flying at 200 miles per hour at sea level. calculate the reynolds number for the flow over the wing root chord. (this is an important number, because as we will see later, it governs the skin-friction drag over that portion of the wing.)b. consider a f-22. the chord length where the wing joins the center body is 21.5 ft. consider the airplane making a high-speed pass at a velocity of 1320 ft/s at sea level (mach 1.2). calculate the reynolds number at the wing root.

The lights used by mark watley (played by matt damon) during the film the martian seem to be metal halide lamps. metal halide lamps are filled with vaporized mercury and metal-halogen compounds. when an electric current is passed through the lamp, the tube begins to glow a bright white/blue color. if you were to pass this light through a prism to separate the individual light frequencies, you would see a rainbow just as you would if using natural sunlight because of the complexity of the metal halide gas and the vast amount of possible electron transitions. (the study of light in this way is known as spectroscopy and allows astronomers to know exactly what atoms compose distant stars, simply by looking at the light they emit. the spectral lines an atom produces uniquely identifies that atom just like a fingerprint uniquely identifies a person. the momentum equation and energy equation that we have used above can be combined to give the following equation: c = e p where again p is the phonon momentum, e is the photon energy and c is the speed of light. when you divide the photon energy found in #6 by the photon momentum found in #4, do you get the speed of light? (if not, check your work for questions #4 through #6). yes no

Brutus, the dog, is pulling a bone to the left with a force of 20 n. lassie, another dog, is pulling a bone to the right with a force of 18n. what is the net force? a. b. c.

What is special about a dc circuit ?