The aluminum alloy (2024-t6) absorber plate is 6 mm thick and well insulated on its bottom. the top surface of the plate is separated from a transparent cover plate by an evacuated space. the tubes are spaced a distance / of 0.20 m from each other, and water is circulated through the tubes to remove the collected energy. the water may be assumed to be at a uniform temperature of 7z 60c. under steady-state operating conditions for which the qhw radiation heat flux to the surface is trad 800 w/m2 , what is the maximum temperature on the plate and the heat transfer rate per unit length of tube? note that trad represents the net effect of solar radiation absorption by the absorber plate and radiation exchange between the absorber and cover plates. you may assume the temperature of the absorber plate directly above a tube to be equal to that of the water.

During physical science, ms. greene challenged her students to produce an energy transformation. james and jill wrapped a 4-inch nail with a coil of fifty turns of wire. they connected one end of the coil to one terminal of a knife switch. they connected the other terminal of the knife switch to the battery. finally, they connected the end of the coil to the other terminal of the battery. james held the tip of a 1-inch nail near the flat end of the 4-inch nail. jill closed the knife switch quickly and then opened it. the 1-inch nail was pulled toward the 4-inch nail. what is the best explanation of why the nail moved? a) electrical energy was converted to mechanical energy in the 1-inch nail. b) the 4-inch nail became an electromagnet and the magnetic force attracted the 1-inch nail. c) the electric current in the 4-inch nail was converted to mechanical energy in the 1-inch nail. d) the 4-inch nail had a positive charge and the 1-inch nail had a negative charge. opposites attracted.

Aball tossed vertically upward from the ground next to a building passes the bottom of a window 1.8 s after being tossed and passes the top of the window 0.20 s later. the window is 2.0 m high from top to bottom. what was the ball's initial velocity? the unit vector j^ is directed upward. how far is the bottom of the window from the launch position? how high does the ball rise above the launch position?

Who was the first scientist to measure speed as distance over time?