The diagram shows a person using a piece of gym equipment to lift weights. which best describes the body in terms of simple machines. the knees are inclined planes, and the lower legs hold the loads. the ankles are the fulcrums. the lower legs are inclined planes, and the knees hold the loads. the ankles are the fulcrums. the lower legs are levers, and the knees are fulcrums. the ankles hold the loads. the knees are levers, and the lower legs are fulcrums. the ankles hold the loads.

Which type of current is produced by a wire breaking magnetic field lines and changing the polarity? a. alternating b. direct c. straight d. alternating and direct

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.

The dot diagram represents the motion of the motorcycle as it moves from left to right