Will mark as brainliest if !
light passes straight from substance a into substance b without being refracted. what could the two substances be?
a. a could be water (speed of light = 225,000 km/s); b could be air (speed of light = 300,000 km/s).
b. a could be glass (speed of light = 200,000 km/s); b could be water (speed of light = 225,000 km/s).
c. a could be ruby (speed of light = 170,000 km/s); b could be sapphire (speed of light = 170,000 km/s).
d. a could be water (speed of light = 225,000 km/s); b could be diamond (speed of light = 120,000 km/s).

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

An object weighs 40n in air, weighs 20n when submerged in water and 30n when submerged in a liquid of unknown density. what is the density of the liquid?

Two objects of different mass start from rest, are pulled by the same magnitude net force, and are moved through the same distance. the work done on object 1 is 900 j. after the force has pulled each object, object 1 moves twice as fast as object 2. how much work is done on object 2?