Your boss asks you to design a room that can be as soundproof as possible and provides you with three samples of material. the only information on each sample's label is the material's coefficient of absorption. the coefficient of absorption listed on sample a is 30%, on sample b is 47%, and on sample c is 62%. when your boss asks for your choice and the reasoning behind it, what would you tell him? a. sample c would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest. b. sample a would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest. c. sample a would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the largest. d. sample c would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the largest.

Copper has free electrons per cubic meter. a 71.0-cm length of 12-gauge copper wire that is 2.05 mm in diameter carries 4.85 a of current. (a) how much time does it take for an electron to travel the length of the wire? (b) repeat part (a) for 6-gauge copper wire (diameter 4.12 mm) of the same length that carries the same current. (c) generally speaking, how does changing the diameter of a wire that carries a given amount of current affect the drift velocity of the electrons in the wire?

Follow these directions and answer the questions. 1. set up the ripple tank as in previous investigations. 2. bend the rubber tube to form a "concave mirror" and place in the ripple tank. the water level must be below the top of the hose. 3. generate a few straight pulses with the dowel and observe the reflected waves. do the waves focus (come together) upon reflection? can you locate the place where the waves meet? 4. touch the water surface where the waves converged. what happens to the reflected wave? 5. move your finger twice that distance from the hose (2f = c of c, center of the curvature) and touch the water again. does the image (the reflected wave) appear in the same location (c of c)? you may have to experiment before you find the exact location. sometimes it is hard to visualize with the ripple tank because the waves move so quickly. likewise, it is impossible to "see" light waves because they have such small wavelengths and move at the speed of light. however, both are examples of transverse waves and behave in the same way when a parallel wave fronts hit a curved surface.

The difference between a red shift and a blue shift has to do with wavelength frequency. t or f