Orbital Power
Most recent answer: 01/29/2012
Q:
Hi,
I am a Master of Science student in Sweden. I would be grateful if you might help me with a difficult problem in mechanics that I have tried to solve for a long time without success. The problem is a part of a bigger problem that I am trying to solve and is therefore important to me. Here is the problem:
How much power P [W] is needed to force a satellite (modeled as a point particle) to move in a perfect circular orbit with radius r [m]? The mass of the satellite is m [kg] and its tangential speed v [m/s] is constant.
Important conditions:
- It is assumed that NO GRAVITY affects the satellite!
- The mass loss due to fuel consumption is neglected.
- The power is assumed to act under ideal conditions, i.e. there is no energy loss due to friction or the choice of engine.
- It is also assumed that v
- Oscar Carlsson (age 20)
Sweden
- Oscar Carlsson (age 20)
Sweden
A:
F⋅v = 0.
Mike W.
Mike W.
(published on 01/29/2012)
Follow-Up #1: gravity-free orbit
Q:
If there's no gravity influencing the satellite, then there's no orbit! Orbit = moving "straight" in a curvated spacetime. No curvature, i.e. no gravity = moving in a straight line. By the way, power = energy consumption over time. The only thing need is acceleration which is a = F / m. Also, there's nowhere in our universe where there is no gravitationnal influence! The main problem with theories is, they always work perfectly in an perfect universe...
- Anonymous
- Anonymous
A:
Maybe this orbit is supposed to be maintained by a long string. The original question didn't specify, except to ask us to neglect gravity.
Mike W.
Mike W.
(published on 01/29/2012)