Scatch space mod prob. is need a formula and answer check

In summary, the conversation discusses the calculation of the speed and time of the command module's 1 revolution around the moon. The formula Vcm^2 = GMm/Ro is used to calculate the speed, resulting in a value of 1634 m/s. However, there is a discrepancy in the calculation of the time, with one person using Kepler's 3rd law and the other dividing the circumference by the speed. Ultimately, it is determined that both methods result in the same answer. The conversation also mentions the mass of the moon and the correct answer for its value.
  • #1
cowgiljl
63
1
i think i got it right it wants to know the speed of the command module and the time it takes to do 1 revolution
mass moon = 7.35E22 kg
radius moon = 1.74E6 m
altitude 60 mi

fromula used was Vcm^2 = GMm/Ro

the speed of the module was 1634 m/s

The time formula thans to enigma was

P = 2\pi \sqrt{\frac{a^3}{\mu}}}
T = 6511 seconds/60
T = 108 min

is this right?
 
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  • #2
Your speed looks correct, using your value for mass of the moon.

But I don't follow what you're doing to get the period.

I'm using Kepler's 3rd law:
[tex]T^2 = (\frac{4\pi^2}{GM_m})r^3[/tex]
and here r = (1.74 x 106 + 1609 x 60) so using G=6.67x10-11 and Mm=7.35x1022 I'm getting
T = 7063 s or 118 min.

(Incidentally, my book lists the mass of the moon as 7.36x1022 kg, but what's a mere 100,000,000,000,000,000,000 kg among friends?)
 
  • #3
you re right gnome

I wrote down and typed the wrong answer but my calculations were correct. the mind was quicker than the pen

thanks again
 
  • #4
Sometimes its good to step back & think about what we're doing.

While I was walking my dog, I was wondering why we're using that crazy formula to get the time of 1 revolution. (Heresy -- calling Kepler's 3rd law a crazy formula! )

We already know the speed. Just divide the circumference of the orbit by the speed & get the same answer.]
 

1. What is Scratch space mod prob?

Scratch space mod prob is a term used in computer science to refer to the amount of temporary storage or memory that is allocated for a particular process or task. It is commonly used in programming languages to optimize memory usage and improve the performance of a program.

2. Why is a formula needed for Scratch space mod prob?

A formula is needed for Scratch space mod prob because it helps to determine the appropriate amount of space needed for a specific task or process. It takes into account factors such as the size of the data being processed and the capabilities of the system, and provides a more accurate estimate of the required space.

3. How is the formula for Scratch space mod prob calculated?

The formula for Scratch space mod prob is typically based on the amount of data being processed, the size of the system's memory, and the type of operation being performed. It may also take into account other factors such as the number of variables used and the complexity of the algorithm being used.

4. Is it important to check the answer for Scratch space mod prob calculations?

Yes, it is important to check the answer for Scratch space mod prob calculations to ensure the accuracy of the formula and the appropriate allocation of memory. This can help prevent errors and improve the overall performance of the program.

5. Are there any tools or resources available to help with Scratch space mod prob calculations?

Yes, there are various tools and resources available to help with Scratch space mod prob calculations, including online calculators, programming forums, and textbooks or guides on programming and computer science. It is also helpful to consult with more experienced programmers for advice and guidance on optimizing memory usage.

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