31. A hydrogen atom initially at rest and in its ground state absorbs a 100eV photon. If the ejected photoelectron moves in the same direction as the incident photon, find (a) the kinetic energy and speed of the photoelectron and (b) the momentum and energy of the recoiling proton

Ablock of mass 1.5 kg slides down an inclined plane that has an angle of 15. if the inclined plane has no friction and the block starts at a height of 3 m, how much kinetic energy does the block have when it reaches the bottom? acceleration due to gravity is g = 9.8 m/s2. a. 6.8 j b. 50.9 j c. 0 j d. 44.1 j

Suppose water is leaking from a tank through a circular hole of area ah at its bottom. when water leaks through a hole, friction and contraction of the stream near the hole reduce the volume of water leaving the tank per second to cah 2gh , where c (0 < c < 1) is an empirical constant. a tank in the form of a right-circular cone standing on end, vertex down, is leaking water through a circular hole in its bottom. (assume the removed apex of the cone is of negligible height and volume.) (a) suppose the tank is 20 feet high and has radius 8 feet and the circular hole has radius 2 inches. the differential equation governing the height h in feet of water leaking from a tank after t seconds is dh dt = − 5 6h3/2 . if the height of the water is initially 8 feet, how long will it take the tank to empty? (round your answer to two decimal places.)

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