Object X and object Y, of charge +Q and −2Q, respectively, are separated by a distance r0, as shown in the figure. (a) Determine an equation for the magnitude and direction of the electric force that is exerted on object Y from object X in terms of Q, r0, and physical constants, as appropriate.

(b) The charge of object X is changed so that it has a charge of −4Q, and the separation distance between the two objects is changed to 2r0. In a clear, coherent paragraph-length response that may also contain figures and/or equations, predict how the electric force exerted on object Y from object X changes from part (a), and predict how the net charge of the two object system changes from part (a).

19. explain why a magnet from your refrigerator could not be used to lift something as heavy as a car. (chapter 7 – pages 202-203) 20. can a magnet ever have a single pole? explain your answer. (chapter 7 – page 208) 21. what happens to the wavelength of a wave if the frequency is increased? (chapter 9 – pages 280-281) 22. an ocean wave has a wavelength of 10 m and a frequency of 4.0 hz. what is the velocity of the wave? show the appropriate equation from your book and show your work with units. (chapter 9 – page 282) 23. as you sit outside, the sound of a siren becomes lower in pitch. is the emergency vehicle moving away from or towards you? explain how you know. (chapter 10 – page 315-316) 24. why are two astronauts in space unable to hear one another? (chapter 10 – page 307) 25. explain in at least 3 sentences how electromagnetic waves form. (chapter 11 – page 338-339) 26. using the chart on page 345 in your textbook, what are the three types of electromagnetic wave with wavelengths shorter than those of visible light. give an example of each. (chapter 11 – pages 345-351) 27. explain why a leaf usually appears to be green, but a rose typically appears red. (chapter 12 – page 373) 28. what is the difference in light that is refracted compared to light that is reflected? think in terms of speed of light as well as what happens to light waves when they interact with a medium. (chapter 12 – pages 369-370) 29. how are concave and convex lenses different? (chapter 13 – page 408-410) 30. what type of mirror is used in rearview mirrors in cars? why is it important that these mirrors have the warning, “objects in mirror are closer than they appear.”? (chapter 13 – page 405)

Aman throws a football straight into the air. as it rises, it slows down. which type of energy is the football gaining?

Carbon 14 is a naturally occurring stable