Asolid sphere is rolling without slipping down an incline. at the bottom of the incline there is a ramp that creates a "quarter-pipe." a quarter-pipe is one quarter of a circle, when viewed from the side. the sphere is released from rest. 4 m above the bottom of the incline. the sphere rolles without slipping down the incline and back up the quarter-pipe. the sphere leaves the quarter-pipe 30 cm above the bottom of the incline and is launched vertically (straight into the air). (a) (15 points) determine the height above the bottom of the incline the ball will reach after teaving the quarter-pipe. (you may ignore any effects due to air resistance.) (b) (10 points) how would the height determined in part (a) change if the ramp were friction- less. explain, briefly. justifications should be made using concepts from class.

Which statement best describes copper? a. it has a low resistance and prevents charges from moving freely. b it has a high resistance and allows charges to move freely. c. it has a high resistance and prevents charges from moving freely. d. it has a low resistance and allows charges to move freely

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.

Inside of a windmill or a dam is a that is used to transform one type of energy into electrical energy. a. motor b. generator c. transformer d. power pack