A refrigerator has a power of 90 W and is left on for 24 hours. A hair dryer has a power of 900 W and is on for 20 minutes. Which statement correctly
compares the energy used by these devices?
A. The refrigerator uses 6,696,000 J more than the hair dryer.
B. The refrigerator uses 3,224,000 J less than the hair dryer.
C. The refrigerator uses 1,080,000 J less than the hair dryer.
D. The refrigerator uses 7,776,000 J more than the hair dryer.

Will a heavier bowling ball hit pins better than a lighter bsll

Aplanet of mass m 6.75 x 1024 kg is orbiting in a circular path a star of mass m 2.75 x 1029 kg. the radius of the orbit is r 8.05 x107 km. what is the orbital period (in earth days) of the planet tplanet?

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