A box of books weighing 315 N is shoved across the floor by a force of 477 N exerted downward at an angle of 35° below the horizontal. If the coefficient of kinetic friction between the box and the floor is 0.58, how long does it take to move the box 4.20 m starting from rest?

Date chapter motion and speed review part a. vocabulary review directions: write the terms that match each description below in thes complete the sentence in number 13. ich each description below in the spaces provided. the boxed letters will 1. equal forces acting in opposite directions (2 words) 2. occurs when an object's velocity decreases (2 words) 3. sum of all forces acting on an object (2 words) 4. total distance divided by total time (2 words) 5. name for the slant of a line on a graph 6. distance divided by time 7. a push or a pull exerted on a body or object 8. distance and direction of an object from its starting point 9. tendency to resist change in motion 10. measure of how far an object has moved 11. speed and direction of motion 12. rate of change of position at a specific point in time (2 words) 13. the rate of change in velocity is called motion and spe

4. who was the first one to measure the speed of light and conclude that it is finite? 5. who was the first philosopher who thought the speed of light is finite? 13. what is the speed of light numerically? 14. give an example of something moving faster than light 15. give an example for some particles or waves that

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.