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 Benzel January 20th, 2018 09:50 AM

Solving for mass

I have the following formula:

$$m = \frac {4π^2} {GP^2}r1(r1+r2)^2$$

Where:
G = 6.674x10^-11
P = 10 years = 3.154x10^8 seconds
r1 = 4.5x10^12

The task previewed this would be inputed with the values and simplified to:
$$m = 2.6*10^7(4.5*10^{12}+r2)^2$$

but I simply can't solve the formula for that result.

I was hoping someone could walk be through how to get specifically the value:
$$2.6*10^7$$

cause that's where I'm stuck.

Thanks in advance and I hope I put this question in the right place! (First post)

 skipjack January 20th, 2018 10:32 AM

Let's assume $G = (20/3)×10^{-11}$ and $P^2 = 10^{17}$ approximately,
so that $GP^2$ = (2/3)×10^7 approximately.
Let's also approximate $4\pi^2r1$ as 178×10^12.
That means 4$\pi^2r1$/((2/3)×10^7) is about (178/(2/3))×10^5, which is 2.67×10^7.

Did you get something wildly different?

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