A container is given a push across a horizontal, frictionless surface. The container has a mass m, the push gives it an initial speed of vi, and the coefficient of kinetic friction between the container and the surface is μk.(a) Use energy considerations to find an expression for the distance the container moves before it stops. (Use any variable or symbol stated above along with the following as necessary: g.)d = (b) If the initial speed of the container is increased by a factor of 3, determine an expression for the new distance dnew the box slides in terms of the old distance d. d

How does the space charge width change with forward and reverse bias? also, calculate the space charge width for a reverse bias of 4v on a silicon pn junction at t = 300k and doping concentrations of na = 5x1015cm-3 , nd = 5x 1016 cm-3 .

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

What do we mean by the event horizon of a black hole?