Orbits Orbital Requirement Orbital Velocity Period of Moon
Orbits • • Orbital Requirement Orbital Velocity Period of Moon Geosynchronous Orbit Satellite TV, XM/Sirius Satellite Phones Space Elevators – (no kidding, Google it!)
Orbital criterion •
3 Orbit examples • ISS going around earth – Know r, find v – GMm/r 2 = mv 2/r solve for v • Moon going around earth – Know r, find v and T – GMm/r 2 = mv 2/r, solve for v – v = 2πr / T, solve for T • Geosynchronous orbit – Know T and v, find r – GMm/r 2 = mv 2/r, solve for v – v = 2πr /T, solve for r
Example 1 - ISS going around earth •
Example 2 - Period of Moon •
Example 3 - Geosynchronous Orbit •
Geosynchronous Orbit • Velocity – Must maintain orbit – Must match earth’s rotation • Calculation – Find r – Find v • Services – Satellite TV – XM/Sirius http: //electronics. howstuffworks. com/satellite-radio 2. htm – Reporter’s delays, BBC relay – Satellite phones (low orbit) http: //www. iridium. com/About/Iridium. Global. Network/Satellite. Constellation. aspx – Space elevators http: //science. nasa. gov/headlines/y 2000/ast 07 sep_1. htm • (Google it!)
Space Elevator • http: //en. wikipedia. org/wiki/Space_elevator
Orbital and Suborbital • What is an orbit? – Object moving fast enough that as it falls, earth’s surface falls away at same rate. • Suborbital – Exaggerated projectile motion, too slow to be in orbit and limited duration. – Search youtube “spaceshiptwo” video.
Problems • Problem 33 (g on the moon) • Problem 42 ( Four 7. 5 kg spheres) • Problem 29 (mass and weight) • Problem 43 (distance for 1/10 g)
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