If an electric water heater uses 40 kw of power and runs for 8 hours, what is the total amount of energy used? a. 5 kilowatt-hours b. 32 kilowatt-hours c. 48 kilowatt-hours d. 320 kilowatt-hours

In which of the following cases is work being done on an object? question 2 options: pulling a trailer up a hill carrying a box down a corridor suspending a heavy weight with a strong chain pushing against a locked door

Astudent is working in the lab to determine how time affect impulse the student keeps the force the same in each row but changes impact the time some data is shown witch trial has the greatest a student is working in the lab to determine how time affect impulse the student keeps the fours the same in each row but change is the impact time some data shown witch trial has the greatest impulse

Some material consisting of a collection of microscopic objects is kept at a high temperature. a photon detector capable of detecting photon energies from infrared through ultraviolet observes photons emitted with energies of 0.3 ev, 0.5 ev, 0.8 ev, 2.0ev, 2.5ev, and 2.8ev. these are the only photon energies observed. (a) draw and label a possible energy-level diagram for one of the microscopic objects, which has four bound states. on the diagram, indicate the transitions corresponding to the emitted photons. explain briefly. (b) would a spring–mass model be a good model for these microscopic objects? why or why not? (c) the material is now cooled down to a very low temperature, and the photon detector stops detecting photon emissions. next, a beam of light with a continuous range of energies from infrared through ultraviolet shines on the material, and the photon detector observes the beam of light after it passes through the material. what photon energies in this beam of light are observed to be significantly reduced in intensity (“dark absorption lines”)? explain briefly.