You are installing a heat pump whose cop is half the cop of a reversible heat pump. you plan to use the pump on chilly winter nights to increase the air temperature in your bedroom. your bedroom's dimensions are 5.35 m ? 3.6 m ? 2.7 m. the air temperature should increase from 63° f to 68° f. the outside temperature is 35° f, and the temperature at the air handler in the room is 112° f. if the pump's electric-power consumption is 787 w, how long will you have to wait for the room's air to warm if the specific heat of air is 1.005 kj/(kg · c°)? assume you have good window draperies and good wall insulation so that you can neglect the release of heat through windows, walls, ceilings, and floors. also assume that the heat capacity of the floor, ceiling, walls, and furniture are negligible. (assume 1.293 kg/m3 for the density of air.)

Consider the particle-in-a-box problem in 1d. a particle with mass m is confined to move freely between two hard walls situated at x = 0 and x = l. the potential energy function is given as (a) describe the boundary conditions that must be satisfied by the wavefunctions ψ(x) (such as energy eigenfunctions). (b) solve the schr¨odinger’s equation and by using the boundary conditions of part (a) find all energy eigenfunctions, ψn(x), and the corresponding energies, en. (c) what are the allowed values of the quantum number n above? how did you decide on that? (d) what is the de broglie wavelength for the ground state? (e) sketch a plot of the lowest 3 levels’ wavefunctions (ψn(x) vs x). don’t forget to mark the positions of the walls on the graphs. (f) in a transition between the energy levels above, which transition produces the longest wavelength λ for the emitted photon? what is the corresponding wavele

You throw a small rock straight up from the edge of a highway bridge that crosses a river. the rock passes you on its way down, 7.00 s after it was thrown. what is the speed of the rock just before it reaches the water 28.0 m below the point where the rock left your hand? ignore air resistance.

The energy equivalent of the rest mass of an electron is