Escape Velocity - Video Tutorials & Practice Problems

a) How fast does a spaceship have to go to escape Earth, starting from the launch pad on the surface? Assume it burns all its fuel very fast and then shuts off the engines.

b) One idea to make getting to space easier is to build a space elevator, a large platform high above Earth's surface where spaceships can land and take off. How high above Earth would this platform have to be for the escape velocity to be 1/5 of its surface value? (For multiple choice, select the correct answer for part (b).)

• A. $2.52\times 10^3$ m
• B. $1.53\times 10^8$ m
• C. $1.59\times 10^8$ m
• D. $7.11\times 10^{10}$ m