12. sarah walks 2 kilometers north from her house to the grocery store. then, she leaves the grocery store and walks 3 kilometers further north to her grandma’s house. she finally leaves her grandma’s house and walks home. b. what is sarah’s distance? a. what is sarah’s displacement?

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.

Avector of magnitude 2 cannot be added to a vector of magnitude 3 so that the magnitude of the resultant is a. zero b. 1 c. 3 d. 5 e. 7

Which of these statements best explains how the hydrosphere interacts with the atmosphere to affect global climate? mountains block rain clouds and cause changes in global rainfall and evaporation. humans burn fossil fuels to produce greenhouse gases which cause global warming. humans cut down trees which affects the amount of oxygen in different parts of the globe. greenhouse gases, like carbon dioxide, dissolve in oceans and prevent global warming.