How Do Satellite Tangential Speeds Compare to Earth's Orbital Momentum?

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Discussion Overview

The discussion revolves around the comparison of tangential speeds of satellites to the Earth's orbital momentum. It explores concepts related to orbital mechanics, including the nature of momentum in orbits, the effects of Earth's rotation on satellite launches, and the implications of Newton's laws of motion in this context.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants assert that tangential speed for satellites is calibrated so that gravity only alters the direction of travel, while others emphasize that any orbiting body possesses momentum without needing to specify it as "initial."
  • It is noted that in a perfectly circular orbit, tangential speed remains constant, but this is not the case for elliptical, parabolic, or hyperbolic orbits.
  • One participant claims that every object on Earth has the velocity required to orbit the Sun, and launching a satellite eastward from Earth utilizes the rotational speed of the Earth to achieve orbital velocity more efficiently.
  • Another participant discusses the implications of Newton's Second Law, suggesting that the force exerted by Earth accelerates objects in the direction of the force, particularly emphasizing the advantage of launching from near the equator due to the Earth's rotational speed.

Areas of Agreement / Disagreement

Participants express a mix of agreement and disagreement regarding the nature of momentum in orbits and the implications of Earth's rotation on satellite launches. There is no clear consensus on the specifics of these concepts, and multiple viewpoints are presented.

Contextual Notes

Some claims depend on the definitions of momentum and tangential speed, and the discussion does not resolve the complexities of different orbital types or the nuances of launching from various latitudes.

avito009
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Tangential speed is the linear speed of something moving along a circular path. So for a satellite the tangential speed of the satellite is just right so that gravity only has the effect of changing the direction of travel.

So now can we compare this satellite to the Earth? Since the Earth has some initial momentum - it is moving in a direction,which is perpendicular to the direction of the Sun from the Earth.

So that means both the satellite and the Earth have (Initial) momentum that prevents them from getting close to the Sun or Earth (In case of satellite).
 
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You don't need the "initial" part. Any orbiting body possesses momentum.

avito009 said:
Tangential speed is the linear speed of something moving along a circular path. So for a satellite the tangential speed of the satellite is just right so that gravity only has the effect of changing the direction of travel.

In a perfectly circular orbit, yes. Objects in elliptical, parabolic, or hyperbolic orbits will not have a steady speed.
 
You are correct. Every object on Earth already has the velocity needed to orbit the Sun, whether it is on Earth or not. To put a satellite in orbit around the Earth, it is easier to launch it toward the East so that its velocity on the surface of the rotating Earth can help it reach the orbital velocity. The advantage is larger on the equator than in the U.S., and there is no advantage at the North Pole.
 
Ok so you mean that according to Newton's Second Law of Motion, the Force Law, the effect of a force on an object is to accelerate it in the direction of the force, according to the formula

F=m a

So the direction of the force of the Earth is towards the East as it rotates towards the East. Now if we were near the Equator we would move at 1000 mph speed. So a spacecraft launched from near the equator would need lesser fuel and would acquire the speed of 1000 mph. So since the direction of force is to the East and velocity is 1000 mph then the satellite also travels in the direction of this force.
 

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