A positively charged particle is at rest on the positive z-axis in reference frame S. Reference frame S′ is moving along the positive x-axis of S, reference frame S′′ is moving along the negative x-axis, and reference frame S′′′ is moving along the positive y-axis, all with speed v relative to S. The axes of all the reference frames are oriented the same way, and their origins coincide at instant t = 0, when observers in each reference frame make measurements.
In which reference frames do observers measure an electric field?
Check all that apply.

a) S b) S′ c) S′′ d) S′′′

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.

2. -/1 pointsserpse10 2.7.p.017.mi. an object moving with uniform acceleration has a velocity of 14.0 cm/s in the positive x direction when its x coordinate is 2.97 cm. if its x coordinate 2.85 s later is -5.00 cm, what is its acceleration? cm/s2 need ? read it master it

Ascientific blank must be testable and capable of being proven false?