Remarks The amount of work calculated in part (c) is negative because an externa
ID: 2203647 • Letter: R
Question
Remarks The amount of work calculated in part (c) is negative because an external agent must exert a force against the direction of motion of the asteroid. It would take a thruster with a megawatt of output about 24 years to slow down the asteroid to half its original speed. An asteroid endangering Earth need not be slowed that much: A small change in its speed, if applied early enough, will cause it to miss Earth. Timeliness of the applied thrust, however, is important. By the time you can look over your shoulder and see the Earth, it's already far too late, despite how these scenarios play out in Hollywood. Last-minute rescues won't work!
Question As the asteroid approaches Earth, the gravitational potential energy associated with the asteroid
Explanation / Answer
decreases.