Gravitational Potential Energy - Video Tutorials & Practice Problems

How much energy is required to move a 1000-kg object from Earth's surface to a height twice Earth's radius?

• A. $3.13\times 10^{10}$ J
• B. $4.17\times 10^{10}$ J
• C. $7.83\times 10^{23}$ J
• D. $8.46\times 10^{23}$ J

You launch a rocket with an initial speed of $5\times 10^3$ m/s from Earth's surface. At what height above the Earth will it have ¼ of its initial launch speed? Assume the rocket's engines shut off after launch.

• A. $9.57\times 10^5$ m
• B. $1.47\times 10^6$ m
• C. $7.84\times 10^6$ m
• D. $2.02\times 10^{22}$ m