1. Two forces F~ 1 and F~
2 are acting on a block of mass m=1.5 kg. The magnitude of
force F~
1 is 12N and it makes an angle of θ = 37◦ with the horizontal as shown in
figure-1. The block is sliding at a constant velocity over a frictionless floor.
Figure-1
(a) Find the value of the normal force on the block.
[3 marks]
(b) Find the magnitude of force F~
2 that is acting on the block
[4 marks]
(c) Find the magnitude of force F~
2 if the block accelerates with a magnitude of
a = 2.5 m/s2 along the direction of F~
2 . [3 mark

What statements accurately describe atoms

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 statement best describes copper? a. it has a low resistance and prevents charges from moving freely. b it has a high resistance and allows charges to move freely. c. it has a high resistance and prevents charges from moving freely. d. it has a low resistance and allows charges to move freely