Anail is partially inserted into a block of wood, with a length of 0.0300 m protruding above the top of the block. to hammer the nail in the rest of the way, you drop a 20.0 kg metal cylinder onto it. the cylinder rides on vertical tracks that exert an upward friction force of 16.0 n on the cylinder as it falls. you release the cylinder from rest at a height of 1.50 m above the top of the nail. the cylinder comes to rest on top of the block of wood, with the nail fully inside the block. use the work-energy theorem to find the speed of the cylinder just as it hits the nail.

If you were to drop a rock from a tall building, assuming that it had not yet hit the ground, and neglecting air resistance. what is its vertical displacement (in m) after 6 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.

Which notation is used to represent an alpha particle? a. b. c. d.