An asteroid is seen traveling directly toward Earth. It's velocity is 7.8500 x 102 m/s when it's 2.0000 x 106 m away from the surface of the Earth. How fast will the asteroid be moving when it collides with the surface of Earth? Assume that the radius of the Earth is 6.3570 x 106 m and the mass of Earth is 5.9720 x 1024 kg. Ignore any effects from air resistance

Hydroelectricity provides about 7 percent of the electricity generated in the united states. (a) explain how a hydroelectric power plant converts energy stored in water into electricity. (b) identify two factors that determine the amount of electricity that can be generated by an individual hydroelectricity power plant. (c) describe the two main types of land-based hydroelectric power plants. (d) describe two economic advantages and two environmental disadvantages of hydroelectricity.