PH 125 Midterm: ph125_s14_exam4-SOLN
Document Summary
Ph125 exam iv: solutions: the space shuttle releases a 470 kg satellite while in an orbit 280 km above the surface of the earth. A rocket engine on the satellite boosts it to a geosynchronous orbit. How much energy is required for the orbit boost? (note: the earth"s radius is 6378 km, its mass is 5. 98 1024 kg, and. Hint: geosynchronous" means the satellite"s period t is 24 hrs. ) Solution: for a geosynchronous orbit, the period t is 24 hr. Using kepler"s law, we can nd the distance from the earth"s center for this orbit: Thus, the satellite changes its orbit to 42, 300 km starting from h = 280 km above the earth"s surface, a distance re + h from the earth"s center. Remember that it is the distance from the earth"s center, not its surface, which is important for gravitation. This will clearly change the satellite"s potential energy, but its kinetic energy will also change.
