Ow does an electric generator work? the axle rotates the armature in the magnetic field of a permanent magnet, which induces an electric current. the armature rotates the axle in the magnetic field of a permanent magnet, which induces an electric current. the axle rotates the armature in the magnetic field of an electromagnet, which induces an electric current. the armature rotates the axle in the magnetic field of an electromagnet, which induces an electric current.

Which example has gravitational potential energy? a. a horse slowing down from a run b. an apple about to fall from a tree branch c. a bicycle being pedaled down a horizontal path d. beaker sitting on the floor

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.

You have a pick-up truck that weighed 4,000 pounds when it was new. you are modifying it to increase its ground clearance. when you are finished