What is the angular momentum of the moon orbiting an Earth-like planet?

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SUMMARY

The angular momentum of the moon orbiting an Earth-like planet is calculated to be 3.65 x 10^27 kgm²/s. This value is derived using the formula L = Iω, where I is the moment of inertia calculated as I = 2/5mr², and ω is the angular velocity determined by ω = 2π/T, with T being the orbital period of 29.3 days. The mass of the moon is 6.23 x 10^22 kg, and its radius is 1040 km. The center-to-center separation between the planet and the moon is 649,000 km.

PREREQUISITES
  • Understanding of angular momentum and its formula L = Iω
  • Knowledge of moment of inertia calculation using I = 2/5mr²
  • Ability to convert orbital period from days to seconds
  • Familiarity with angular velocity calculation using ω = 2π/T
NEXT STEPS
  • Learn about the conservation of angular momentum in orbital mechanics
  • Study the effects of mass distribution on moment of inertia
  • Explore gravitational interactions between celestial bodies
  • Investigate the dynamics of satellite orbits around planets
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Astronomy students, physicists, and anyone interested in celestial mechanics and orbital dynamics will benefit from this discussion.

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Hi, can anyone help me get started on this problem...I am totally lost and don't know what equation to use...thanks a lot

There is a moon orbiting an Earth-like planet. The mass of the moon is 6.23 x 10^22 kg, the center-to-center separation of the planet and the moon is 649000 km, the orbital period of the moon is 29.3 days, and the radius of the moon is 1040km. What is the angular momentum of the moon about the planet.
 
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they are talkin about point mass angular momentum

L = r x p (the linear v is 90 degrees to the radius therefore) = r*p while p = mv and u can figure out the linear veloctiy useing the orbital period.

29.3 days to go 2pi radians so... w = 2pi/(29.3 days) and v = wr so u get...

L = r^2 m (2pi)/(29.3 days)
 


To solve this problem, we can use the equation for angular momentum, which is L = Iω, where L is the angular momentum, I is the moment of inertia, and ω is the angular velocity.

First, we need to calculate the moment of inertia of the moon. This can be done using the formula I = 2/5mr^2, where m is the mass of the moon and r is its radius. Plugging in the given values, we get I = 2/5(6.23 x 10^22 kg)(1040km)^2 = 1.37 x 10^33 kgm^2.

Next, we need to find the angular velocity of the moon. This can be calculated using the formula ω = 2π/T, where T is the orbital period. Plugging in the given value of 29.3 days (which needs to be converted to seconds), we get ω = 2π/(29.3 days * 24 hours/day * 60 minutes/hour * 60 seconds/minute) = 2.66 x 10^-6 rad/s.

Now, we can plug in our calculated values into the equation for angular momentum: L = (1.37 x 10^33 kgm^2)(2.66 x 10^-6 rad/s) = 3.65 x 10^27 kgm^2/s.

Therefore, the angular momentum of the moon orbiting an Earth-like planet is 3.65 x 10^27 kgm^2/s.
 

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