Based on Newton’s third law of motion, will a tennis ball go farther if it hits a tennis racquet that is still or one that is in motion? One that is still because it will absorb all of the force of the ball.
One that is still because that will have a greater impact on the trajectory.
One that is in motion because both the ball and the racquet will contribute momentum.
One that is in motion because the racquet’s force will cancel the ball’s force out.

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

Alfred pushes on a heavy box, but cannot move it. the box has a lot of inertia motion friction gravity

Could someone . i have tried to solve myself but my calculation is off