Three friends tie three ropes in a knot and pull on the ropes in different directions. Adrienne (rope 1) exerts a 20-N force in the positive x-direction, and Jim (rope 2) exerts a 40-N force at an angle 53∘ above the negative x-axis. Luis (rope 3) exerts a force that balances the first two so that the knot does not move.
a. Use equilibrium conditions to find F LonKx and F LonKy.
b. Use equilibrium conditions to determine the magnitude of F⃗ LonK.
c. Use equilibrium conditions to determine the angle θ that describes the direction of F⃗ LonK. Use positive values if the force is directed above the positive x-axis and negative values if it is directed below the positive x-axis.
d. Construct a force diagram for the knot.

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

Which of these statements best explains how the hydrosphere interacts with the atmosphere to affect global climate? mountains block rain clouds and cause changes in global rainfall and evaporation. humans burn fossil fuels to produce greenhouse gases which cause global warming. humans cut down trees which affects the amount of oxygen in different parts of the globe. greenhouse gases, like carbon dioxide, dissolve in oceans and prevent global warming.

Four friends, a, b, c, and d are standing varying distances away from a speaker which is producing sound waves.