Chapter 1: Q62P (page 429)
(a) Calculate how much work is required to launch a spacecraft of mass m from the surface of the earth (mass, radius) and place it in a circular low earth orbit鈥攖hat is, an orbit whose altitude above the earth鈥檚 surface is much less than. (As an example, the International Space Station is in low earth orbit at an altitude of about 400 km, much less than.) Ignore the kinetic energy that the spacecraft has on the ground due to the earth鈥檚 rotation. (b) Calculate the minimum amount of additional work required to move the spacecraft from low earth orbit to a very great distance from the earth. Ignore the gravitational effects of the sun, the moon, and the other planets. (c) Justify the statement 鈥淚n terms of energy, low earth orbit is halfway to the edge of the universe.鈥
Short Answer
- The work required to launch a spacecraft in orbit is,.
- The minimum amount of addition work required is, .
- The work required to bring a satellite into orbit was the same as that required to bring the satellite from orbit to the edge of space.