View Full Version : Physics Question
Sharpay21355
Oct 2, 2011, 06:00 PM
A satellite with an orbital period of exactly 24.0 h is always positioned over the same spot on Earth. This is known as a geosynchronous orbit. Television, communication, and weather satellites use geosynchronous orbits. At what distance would a satellite have to orbit Earth in order to have a geosynchronous orbit?
Unknown008
Oct 2, 2011, 11:12 PM
Use the formula for gravitational acceleration and centripetal acceleration (or force due to gravity and force required for circular motion) and equate them together. What can you come up with?
ebaines
Oct 12, 2011, 06:31 AM
Any distance, it just needs to have a velocity to match the distance
Sorry - this is wrong. The definition of a satellite being in orbit is that it circles the earth in free fall without any other means of propulsion. If the satellite is too close to the earth and matches the speed of rotation so as to stay above a single point on the earth's surface it will be traveling too slowly to stay in orbit (and will crash to earth). Think of a helicopter hovering overhead - it's "geosynchronous" in that is remains above one spot, but it's not considered to be in orbit. Turn off the helicopter's engine and guess what happens?
If the satellite is too far away then its speed would have to be too great to stay in orbit and it will escape earth's gravity and fly out into space.
Abhimanyu Pudi
Oct 3, 2012, 10:53 PM
Come on fellas, it means that such a satellite appears to be at rest with respect to a particular point on earth. Its 36000km
Abhimanyu Pudi
Oct 3, 2012, 10:54 PM
They are called geostationary satellites.
chicas2013
Apr 14, 2013, 04:22 PM
I wish I knew the answer!
I am stuck with his one?
A 3,647 KG elevator is pulled upward by a constant tension force. The elevator starts at rest and under the influence of this constant tension force, accelerates upwards so that its speedis 6.82 m/s when it located 6.0 m above its initial location. What is the average power that the tension in the cable exerts on the elevator? Assume that the only force acting on the elevator is gravity. Write your answers in kW (kilo-watts) to three significant figures. (Hint: how long does it take for the situation to occur?
What’s the ratio of the instantaneous power exerted on the elevator by the tension in the cable when the elevator’s height is 2.74 m above its initial point tit he average power calculated in the question above? Write your answers to three significant figures( Hint you can use your calculations of the energy transferred to the elevator by the cable to determine the magnitude of the tension force)
ebaines
Apr 14, 2013, 05:07 PM
chicas2013 - pease don't double-post questions. You posted this question here:
https://www.askmehelpdesk.com/physics/free-physics-answers-744301.html
And that's where you can expect a response.