AST101H1 Lecture Notes - Lecture 7: Escape Velocity, Weightlessness, Rubber Band

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Bryan Gaensler

Document Summary

20m/s. (if there was no air resistance: therefore, we say that the acceleration of gravity is about 10 meters per second squared. Free fall: the condition in which an object is falling without resistance; objects are weightless when in free fall. Free fall happens when there is nothing to prevent you from falling. e. g. if an elevator cable breaks, you experience free fall because the floor of the elevator falls at the same rate as you are falling. Total orbital energy = gravitational potential energy + kinetic energy. Escape velocity: objects that gain orbital energy moves into an orbit with a higher average altitude, e. g. If you start from an elevated surface, it takes less energy and hence lower velocity to escape because gravity weakens with distance. Gravity attracts earth and the moon toward each other but it affects different parts of earth slightly differently because the strength of gravity declines with distance.