Check my math

Summary:

Would a physicist guru mind checking my math?

Check my math

JamesJJlm 05 Apr 2011 13:49

At http://wiki.answers.com/Q/What_is_the_mass_of_Mount_Everest&updated=1&waNoAnsSet=2

there were 2 very incorrect answers for a pretty hard question. While I was checking NASA's math for the CME, I ran across it and wanted to fix it. Oba or Biken or anyone that knows physics, can you check the math and make sure I got it right? My answer is the 3rd one. I would really appreciate it.

Edit: I just changed it again. For some reason I used 50 meters as the height, obviously not correct…fixed it.

Last edited on 05 Apr 2011 13:56 by JamesJJlm Show more

Re: Check my math

bikenbeer2000 05 Apr 2011 15:25

Using the figures for the base radius and height as well as the formula for the volume of a cone given in the second answer, I get 6.48 x 10¹² tonnes, which is pretty much in agreement with your answer.

Re: Check my math

obaeyens 05 Apr 2011 17:52

This could help :-)

http://www.wolframalpha.com/input/?i=+124.8+pound%2Fcubic+foot++to+kilogram%2Fcubic+meter

Volume Cone:

(1)

\begin{align} V=\frac{1}{3}\pi r^2h \end{align}

Now h= 8,848 m, r=16,093 m

(2)

\begin{align} V=\frac{1}{3}\times \pi \times 16,093^2\times 8,848 \text{ = } 2.39965\times 10^{12} \text{ m}^{3} \end{align}

Density:

(3)

\begin{align} M=V\times D \end{align}

$D=1999.1 kg/m^{3}$

(4)

\begin{align} M=2.39965\times 10^{12} \times 1999.1 \text{ = } 4.79714\times 10^{15} \text{ Kg} \end{align}

Density:
$D=2700 kg/m^{3}$

(5)

\begin{align} M=2.39965\times 10^{12} \times 2700 \text{ = } 6.47905*10^{15} \text{ Kg} \end{align}

Last edited on 05 Apr 2011 19:09 by obaeyens Show more

Re: Check my math

JamesJJlm 05 Apr 2011 19:03

I'm not really sure what you mean here. You're using square meters rather than cubic meters?

Also most rock is around 2500kg/m. Not sure where you got 1999.1.

The reason my answer slightly differs from Biken's is because I used 0.33 in my calculation instead of 1/3. It was just easier to type out.

Re: Check my math

obaeyens 05 Apr 2011 19:10

Oops corrected.

Re: Check my math

obaeyens 05 Apr 2011 19:11

Also most rock is around 2500kg/m. Not sure where you got 1999.1.

That example on the link

Re: Check my math

JamesJJlm 05 Apr 2011 19:41

Yeah well anyways. For anyone wanting the comparison between Mt. Everest and an average CME mass:

1,600,000,000,000 kg (CME)
6,480,000,000,000,000 kg (Mt. Everest)

Thats a large difference there. Its like throwing a newborn kitten at an african elephant. And thats just one mountain.

Re: Check my math

obaeyens 05 Apr 2011 19:56

Its like throwing a newborn kitten at an african elephant.

I love your wording. LOL

And it also means that you get a 1000 more attraction force from Mount Everest if they would be at the same distance!

Re: Check my math

obaeyens 05 Apr 2011 20:15

Oh yes about the newborn kitten it is even worse.
It is not the CME versus Mount Everest. It is the CME versus the complete Earth!
Calculate how many Mount Everests can go into on Earth. LOL

I also calculated the inner core mass to be $1.13227*10^{23}$ Kg

Last edited on 05 Apr 2011 20:16 by obaeyens Show more

Re: Check my math

JamesJJlm 06 Apr 2011 12:34

Hey I have one question though. The CME equates to about 8*10^-19% of mass compared to the sun (.0000000000000000008%). So what keeps the sun from releasing more of it's mass? Why only these "puny" CME's?

Also another question, does the sun's mass decrease over time due to CME's being released, and solar wind?

Re: Check my math

DieselHorseLAW 06 Apr 2011 14:41

This is an interesting question, of course I don't have an answer at the moment, but I will look forward to one.

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“In all matters of opinion, our adversaries are insane.” - Oscar Wilde

Re: Check my math

JamesJJlm 06 Apr 2011 15:03

Makes me wish there were an "Ask a Solar Physicist" website with someone like David Morrison.

Re: Check my math

JamesJJlm 06 Apr 2011 15:20

Answered one of my own questions:

The Sun’s mass is actually slowly decreasing over time. There are two processes at work here. The first is the fusion reactions in the core of the Sun, converting atoms of hydrogen into helium. Some of the Sun’s mass is lost through the fusion process, as atoms of hydrogen are converted into energy. The warmth we feel from the Sun, is the Sun’s lost mass. The second way is the solar wind, which is constantly blowing protons and electrons into outer space.

From http://www.universetoday.com/47600/solar-mass/

Re: Check my math

DieselHorseLAW 06 Apr 2011 15:32

So if what PG claimed was true, and it threw off some mega flare so often then wouldn't the sun be a lot different than it is now seeing as every time it does a normal CME is loses mass, now looking at the "enormous flare", imagine how much mass it would lose.

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“In all matters of opinion, our adversaries are insane.” - Oscar Wilde

Re: Check my math

obaeyens 06 Apr 2011 17:45

So what keeps the sun from releasing more of it's mass?

That is an easy one. It is called gravity ;-)

The reason why parts of the CME gets away is because a fragment of the particles get enough speed to reach the escape velocity caused by an explosion caused by some magnetic fields reconnects.

Re: Check my math

JamesJJlm 06 Apr 2011 20:44

Ok, that makes sense. Also slow CME's speed up because they get caught in the solar wind stream, and faster CME's slow down for the same reason.

Do you have any reference for that Oba? Just for the sake of good practice.

Re: Check my math

JamesJJlm 06 Apr 2011 20:55

Responding to Diesel here:

I was working on that math earlier because I was asking myself the same thing. You would think the sun would lose an insane amount of mass since this would have happened around 400,000 times by now. Not to mention the amount of mass the Earth would GAIN by having plasma equal to two inner core masses hit us that many times. Also, are we to assume mercury was never in the line of fire for these flares? It would get absolutely rocked. I think I read somewhere that it has a magnetic field too.

Re: Check my math

DieselHorseLAW 06 Apr 2011 21:14

Yeah, as I have said before, the more you look into it, the less it makes sense.

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“In all matters of opinion, our adversaries are insane.” - Oscar Wilde