Why are black holes considered the "destroyers and creators" of life? A. Black holes play a role in the formation of galaxies that contain stars, which help planets form and (at least for Earth) support life; but they also can subsume celestial bodies and destroy life that passes the event horizon. B. Scientists have discovered that all known matter emanated from the first black hole in the universe, and that all matter will eventually return to be consumed by Sagittarius A*. C. All light in the universe originates from black holes, and light is necessary to support life, but too much light (as stars grow bigger and stronger) will destroy the life it created through fire. D. DNA is formed inside the center of a black hole and shoots out through the Schwarzschild radius, but when a black hole consumes a celestial object that has life on it, the DNA breaks down at the singularity.

What property is a characteristic of a substance that can be observed and does not change the identity of the substance

What is the acceleration of a spaceship that is initially at rest and then speeds up to 220 m/s in 20 seconds

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)