Physics satellite velocity and period

In summary, the tangential velocity of a satellite in a circular orbit 300km above the surface of the Earth is 6.67E-11 m/s.
  • #1
astru025
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0

Homework Statement



a. What is the tangential velocity of a satellite in a circular orbit 300km above the surface of the Earth?

Homework Equations


Velocity of a satellite= v^2= G (Me/r)


The Attempt at a Solution


V^2= 6.67E-11 (5.98E24/6.37E6)
I calculated this and my answer proved incorrect. How do I incorporate the "300 km above Earth's surface" into this equation?.
 
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  • #2
astru025 said:
How do I incorporate the "300 km above Earth's surface" into this equation?.
Use that to calculate the radius of the orbit, which will be "r".
 
  • #3
I use 300km to calculate the radius of the orbit. What is the equation for the radius?
 
  • #4
astru025 said:
I use 300km to calculate the radius of the orbit. What is the equation for the radius?
In your calculation, you set r = radius of the earth. But that's not correct; r should be the radius of the orbit, which is bigger than the radius of the Earth (by the given amount).

First calculate the radius of the orbit, then use it in your formula to find the speed.
 
  • #5
Okay thank you. Is there a special equation to find the radius of the orbit?
 
  • #6
astru025 said:
Is there a special equation to find the radius of the orbit?
Just add the altitude of the orbit, which was given, to the radius of the earth.
 
  • #7
Okay so now I have : v^2= G (6.67E-11) x ((Me (5.98E24) / (r + 300 km. (6670 km))
Is this correct? So I got 244540.39.
 
  • #8
That answer was incorrect. What am I doing wrong?
 
  • #9
Did you check your units? Always check your units.
 
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  • #10
astru025 said:
Okay so now I have : v^2= G (6.67E-11) x ((Me (5.98E24) / (r + 300 km. (6670 km))
Is this correct? So I got 244540.39.
I don't understand how you got that answer. Did you make sure to put the radius in meters, not km?
 
  • #11
This must be it. You are off by a factor of about √1000. The radius should be in meters.
 
  • #12
Okay I finally came up with 1768897.96 m/s
 
  • #13
Okay now I came up with 7733.046. This must be correct. Miscalculation in my previous try.
 
  • #14
This proved correct! Thanks so much. Always need to check my units :)
 

Related to Physics satellite velocity and period

1. What is the formula for calculating the velocity of a satellite?

The formula for calculating the velocity of a satellite in orbit is v = √(GM/r), where v is velocity, G is the gravitational constant, M is the mass of the central body, and r is the distance between the satellite and central body.

2. How does the velocity of a satellite affect its orbit period?

The velocity of a satellite has a direct relationship with its orbit period. As the velocity increases, the orbit period decreases. This is because a higher velocity means the satellite is moving faster around the central body, completing each orbit in a shorter amount of time.

3. Can the velocity of a satellite change?

Yes, the velocity of a satellite can change. This can happen due to external forces such as atmospheric drag, gravitational pull from other celestial bodies, or by using thrusters to adjust the satellite's trajectory.

4. What is the difference between orbital velocity and escape velocity?

Orbital velocity is the minimum velocity required for a satellite to maintain a stable orbit around a central body. Escape velocity is the minimum velocity required for an object to completely break free of a central body's gravitational pull. In other words, orbital velocity keeps a satellite in orbit, while escape velocity allows it to leave orbit.

5. How do scientists measure the velocity and period of a satellite?

Scientists can measure the velocity and period of a satellite using various instruments, such as radar, telescopes, and spacecraft. They can also use mathematical equations and formulas, such as Kepler's laws of planetary motion, to calculate these values based on observations of the satellite's position and motion.

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