14.5 Escape Speed

1. 14.5 Escape Speed Ivan Bernabe Physics period 1 Mrs. Knotts January 13, 2012

2. Escape Speed Diagram

3. Definition: The minimum speed necessary for an object to escape permantyently from a gravitational field that holds it. The minimum speed required to escape from a planets gravitational pull What goes up doesn’t come down

4. Example: When a payload is put into a rocket to be sent into space, a major factor is the speed and the direction of the rocket For the payload to reach the earths orbit , the payload will have to be slightly tilted horizontally to achieve the orbit.

5. Example: For anything to leave the earth, the speed must reach more than 11.2 km/s, as it leaves earth it loses speed and becomes slower, but never stopping Neglecting air speed it will never come back down to earth

6. Question: Neglecting air resistance, what will happen to a projectile that is fired vertically at 8 km/s? At 12 km/s? - At 8 km/s, the projectile fired would not reach the earth’s orbit resulting in the projectile falling back to earth. - At 12 km/s, the projectile would reach the earth’s orbit and start slowing down, but never stop