Satellite in orbit - forces involved

AI Thread Summary
A satellite in orbit experiences free fall, meaning the only force acting on it is gravity. This gravitational force acts perpendicular to the satellite's direction of motion, resulting in no work being done, allowing it to maintain a constant speed and height. The satellite orbits the Earth every 120 minutes, indicating a balance between gravitational pull and its tangential velocity. If another force were to act on the satellite, it would either slow down, causing it to descend, or speed up, leading it to ascend. The discussion also touches on the origin of the exam question, questioning its wording and source.
jsmith613
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Homework Statement


A satellite orbits the Earth once every 120 minutes.
The satellite is in a state of free fall. What is meant by the term free fall? How can the height of the satellite stay constant if the satellite is in free fall? [3 marks]

Homework Equations


none

The Attempt at a Solution


So is this correct:

Free-fall: when the only force acting on an object is the gravitational force
- as the force is acting ppd to direction of motion, no work is done on the satellite
- the satellite moves in a circle at a constant speed at a constant height
 
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Hi jsmith!

jsmith613 said:
So is this correct:

Free-fall: when the only force acting on an object is the gravitational force
- as the force is acting ppd to direction of motion, no work is done on the satellite
- the satellite moves in a circle at a constant speed at a constant height

Yes! :smile:
 
jsmith613 said:

Homework Statement


A satellite orbits the Earth once every 120 minutes.
The satellite is in a state of free fall. What is meant by the term free fall? How can the height of the satellite stay constant if the satellite is in free fall? [3 marks]


Homework Equations


none

The Attempt at a Solution


So is this correct:

Free-fall: when the only force acting on an object is the gravitational force
- as the force is acting ppd to direction of motion, no work is done on the satellite
- the satellite moves in a circle at a constant speed at a constant height

Because the satellite is moving very fast. Another force would either slow the satellite down, so it would move closer to the earth, or speed it up, so it would move away from the earth.
 
jsmith613 said:

Homework Statement


A satellite orbits the Earth once every 120 minutes.
The satellite is in a state of free fall. What is meant by the term free fall? How can the height of the satellite stay constant if the satellite is in free fall? [3 marks]


Homework Equations


none

The Attempt at a Solution


So is this correct:

Free-fall: when the only force acting on an object is the gravitational force
- as the force is acting ppd to direction of motion, no work is done on the satellite
- the satellite moves in a circle at a constant speed at a constant height

I am an exams officer for a UK exam board. Can you let me know where this exam question came from ?.,... is it an exam question or a question from a teacher?

are you sure youhave worded the question correctly??
 
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