G = gravitational constant m = mass 1 (rocket) M = mass 2 (Earth) R = radius (distance between the center of earth and the rocket) V(esc) = escape velocity

Likely something like the force of gravity times mass times something divided by radius is equal to the mass times the escape speed squared divided by two. I think.

this equation is dumb, take out the unnecessary "x"s (representing multiplication), divide both sides by m, move the two to the left side, then take the square root of each. Then you`ll have a useful equaiton for calculating escape velocity of a massive body , given gravitational constant (G), mass of the body(M), and distance from center of gravity (G).

err that last one was supposed to be R, and also the escape SPEED is independant of the escaping objects mass (m), since the velocity will be the same for all masses, with only required force being ifferent.

Throwing out an equation that nerds in specialized fields use then standing back and patting yourself on the back for something obscure is clever? Got to recalibrate my clever meter I guess

This is using the potential energy of a spacecraft/rocket to find escape velocity, This is using the potential energy of a spacecraft/rocket to find escape velocity. Simplify the equation, you get: Escape velocity = sqrt(2GM/R). To solve that, we already have close approximations of G(6.67x10^-11), and for the Earth, its mass and radius. The required escape velocity is rather independent of the mass of the rocket; you have to get it up to that speed, the mass just effects the amount of force required to push it to that speed. So canceling it out of the equation isn`t really a problem.

The escape velocity of Earth comes to about 11.2 kilometers per second from the surface, assuming you launch perpendicular to the ground.

Nobody uses "x"s for multiplication, the "squared" superscript is on the "esc" instead of the whole variable Vesc, and mass is irrelevant for escape velocity.

My science teacher used to say that he did not understand the phrase "Its not Rocket Science!" because Rocket Science is apparently quite easy to get your head around...

Nobody uses "x"s for multiplication, the "squared" superscript is on the "esc" instead of the whole variable Vesc, and mass is irrelevant for escape velocity.

Essentially, you`re solving for V. The equation can be simplified, however, by dividing m off of both sides and multiplying both sides by 2, leaving you with

2GM/R = V^2

From there you can easily take the square root of both sides to leave yourself with V.

`this is stupid. you would understand if you know the variables. it`s rhetorically illogical. `

You are a fool. If you knew anything about this you would know exactly what those variables are; they are very standard im afraid my uneducated friend. It is merely equating gravitational potential energy to the kinetic energy needed to overcome said energy (ie send a rocket into space)

I dont think its supposed to be a joke its just a very geeky numberplate

im fairly certain, it`s an equation that`s used to find orbital speeds, masses, and radii of two gravitating objects in space. basically just newtons second law rewritten to include the motion of a satellite. im a junior in highschool, i dont think its that hard.

I grad with my B.S. in Physics this May. Yay me...

This is just the escape velocity from a 2nd order differential equation. Pretty boring, actually. Although, I would disagree on this being a common equation. You have probably seen the gravitational potential energy equation 9which is very similar) in lower division physics, but this equation doesn`t usually show up until advanced mechanics. But every prof teaches differently.

I worked at a National Lab for 5 years. And yes, most of us are def. not virgins. One of the reasons I left the lab is because everyone is sleeping with each other. Like a big giant nerdy f-fest. Pretty crazy.

"I worked at a National Lab for 5 years. And yes, most of us are def. not virgins. One of the reasons I left the lab is because everyone is sleeping with each other. Like a big giant nerdy f-fest. Pretty crazy."

"I worked at a National Lab for 5 years. And yes, most of us are def. not virgins. One of the reasons I left the lab is because everyone is sleeping with each other. Like a big giant nerdy f-fest. Pretty crazy."

Nice, in a kind of Big Bang Theory way.

-Sometimes the comments on IAB are just as funny if not funnier than the actual post... I love this site. "BORED MEMBERS" FTW!!!!!!

Oh don`t worry. Our proud leader essentially just pronounced his intention to destroy the actual space program with budget cuts that add up to 5 dollars a person a year for the overall population. Don`t get me wrong NASA will still exist but we will not be doing much in the way of the ole man in space bit real soon.

I once met a female physicist at a party. She got her PhD by researching "remote sensing", whatever that is! She was a platinum blonde and she claimed she had a tattoo which read "carpe diem" just below her bikini line. Natrually enough, I asked her if the "carpe" matched the curtains, which I thought was hilarious.....she didn`t!

I looked into it just for kicks. Something to do with using the potential energy of a rocket to find escape velocity. Yeah, I don`t pretend to understand it either.

It`s the energy required for escape velocity. Think of all the names and things about ballplayers and actors you`ve learned over the years. That`s why you don`t have room in your head for things like this.

It`s not the "Trajectory of a Projectile." The equation yields scalar a scalar quantity, while trajectory is a vector.

duffytoler had it right. Notice the "m" term vanishes, indicating escape velocity is dependent on the mass of the planet, not the mass of the spacecraft or projectile. Fun fact for the evening, I suppose.

well the left part of the equation is the gravitational energy it takes to get from 0 to radius R with an object of mass mx away from the mass M. This is the integrated gravitational force -G_x (m_x M)/r^2 from 0 to R. I guess they made a mistake here, because you normally don`t start at 0 but rather at a point with the radius of the mass m (for example the radius of the earth). Although a little extra energy won`t hurt when escaping the Earths pull, I guess that if NASA can`t do any better in math we don`t have to wonder when the space ships crash...

On the other side we have the kinetic Energy of the mass mx, thus by equating these two energies we get the escape velocity V_ESC it takes the Object of mass mx to escape the gravitational pull to mass M.

I`m an electrical engineer so this really is not my field, so you can keep any errors :-D.

Ian you dont have to understand the math lol. People are always saying " what dont you get about (fill in blank)? It`s not rocket science." The equation on the sticker IS actual rocket science lol. Make sense? If you want to understand the actual math, read the comment above yours. :)

I play poker with a guy who works as a rocket scientist for NASA. Whenever he is taking too long to make a decision, we`ll say, "Come on Dave - It`s not rocket science."

This is in reference to the Escape Speed(velocity) required to "escape" from a gravitational field (such as Earth)... I remember doing work with this kind of calculation, and having to use the Schwarzchild radius for singularities...

This one is much better than the red one that says "If this bumper sticker turns blue you`re going too fast" because that was is actually not physically true.

The parts I don`t understand are the "x" symbol. It makes it looks more like their adding another variable instead of multiplying the parameters together.

Also V(esc)^2 looks like their squaring the subscript and not the parameter itself.

It`s the velocity at which rockets can leave the atmosphere, or escape velocity. I don`t really understand how that`s a joke. Probably to confuse people who haven`t taken physics.

"...and she claimed she had a tattoo which read "carpe diem" just below her bikini line. Natrually enough, I asked her if the "carpe" matched the curtains, which I thought was hilarious.....she didn`t!"

Hahahaha! Although most might say that`s a fail, my inner nerd says this is a WIN.

Oh and all US government facilities buy American cars. Which includes the Pontiac GT. At LLNL and LBNL, the directorate usually drive Chrysler 300`s and Cadillac STS`s. My car was a Ford Crown Vic P71. And those are your tax dollars at work, folks!

> MrBored123 > Hi, well the left part of the equation is the gravitational energy it takes to get from 0 to radius R with an object of mass mx away from the mass M. This is the integrated gravitational force -G_x (m_x M)/r^2 from 0 to R...

Your IQ is too high for i-am-bored. Perhaps you`d be happier over at 4chan...

Basically, gravity is `negative` energy, in the sense that if you are in a gravity well, your gravitational potential energy is negative. The best you can get is 0.

So basically, if you add positive kinetic energy (i.e. speed away from the planet) to your gravitational potential energy, it eventually becomes 0, and you escape the gravity well. The speed necessary for this is escape velocity.

So, since you`re saying:

gravitational potential energy + kinetic energy = 0

You are really saying:

-gravitational potential energy = kinetic energy

And therefore, you substitute in 1/2mv^2 for kinetic energy and GmM/R for gravitational potential energy, and end up with a wonderful equation for calculating escape velocity on any given planet.

Rocket science isn`t difficult. There`s minimal friction, predictable behaviors, and a lot of it can be solved through energy equations and a minimum of calculus. No air to worry about, or kinetic friction, or rotational inertia, just objects in space.

Rocket engineering on the other hand is a godawful nightmare I do not want anything to do with.

> catbarf > Rocket science isn`t difficult. No air to worry about, or kinetic friction, or rotational inertia, just objects in space

On the other hand, EVERY atom in the universe exerts a gravitational force upon every OTHER atom in the universe, which would tend to make it a little more difficult if they didn`t just cheat and discount 99.9999999% of them as being `too weak to bother with`.

"@Spider_sol: It`s called "phase shifting" and it`s totally physically true. You`d just have to be going extremely fast."

@nerdtchn: I know phase shifting and I get red shift/blue shift... obviously better than you. Red wouldn`t turn blue, it would shift blue. It would become a slightly oranger color of red.

Ok so G is a constant of proportionality for gravitational pulls between 2 bodies (universal gravitation constant), M and m are the masses of the 2 bodies, R i would assume is the distance between the 2 bodies.

The other side of the equation seems to contain the mass of 1 body and its velocity, so i would assume this equation is what u need to solve in order to put a satelite in a stable orbit around the earth, or maybe to calculate wich distances from the earth can be used as stable orbits for satelites.

- But we`re just not up on our rocket science and astrophysics enough to get the joke. Any geniuses out there?
m = mass 1 (rocket)

M = mass 2 (Earth)

R = radius (distance between the center of earth and the rocket)

V(esc) = escape velocity

just sayin`

Oh thank god I`m not the only one. XD

theyre finding escape velocity by substituting e=GmM/r into e= .05mv^2

m=mass of rocket

M=mass of earth

R=distance between the two

GmM/R=gravitational force

Vesc= Escape velocity

This equation is used to calculate the escape velocity only accounting for the gravitational attraction between the two objects.

The escape velocity of Earth comes to about 11.2 kilometers per second from the surface, assuming you launch perpendicular to the ground.

Nobody uses "x"s for multiplication, the "squared" superscript is on the "esc" instead of the whole variable Vesc, and mass is irrelevant for escape velocity.

Try v = sqrt(2GM/r)

Meh.. I still don`t get it..

Try v = sqrt(2GM/r)

Thank you! Now I get it.

m = Vehicular mass (factor it out)

M = Planetary mass

R = Radius of the planet

Vesc = Escape velocity

Where V stands for the escape velocity.

Essentially, you`re solving for V. The equation can be simplified, however, by dividing m off of both sides and multiplying both sides by 2, leaving you with

2GM/R = V^2

From there you can easily take the square root of both sides to leave yourself with V.

They made this seemingly complicated on purpose.

For every action there is an equal and opposite reaction.

Understand that and you understand rockets.

Yep. 1upper.

You are a fool. If you knew anything about this you would know exactly what those variables are; they are very standard im afraid my uneducated friend. It is merely equating gravitational potential energy to the kinetic energy needed to overcome said energy (ie send a rocket into space)

I dont think its supposed to be a joke its just a very geeky numberplate

This is just the escape velocity from a 2nd order differential equation. Pretty boring, actually. Although, I would disagree on this being a common equation. You have probably seen the gravitational potential energy equation 9which is very similar) in lower division physics, but this equation doesn`t usually show up until advanced mechanics. But every prof teaches differently.

I worked at a National Lab for 5 years. And yes, most of us are def. not virgins. One of the reasons I left the lab is because everyone is sleeping with each other. Like a big giant nerdy f-fest. Pretty crazy.

Nice, in a kind of Big Bang Theory way.

Nice, in a kind of Big Bang Theory way.

-Sometimes the comments on IAB are just as funny if not funnier than the actual post... I love this site. "BORED MEMBERS" FTW!!!!!!

Funny bumper sticker btw!

She was a platinum blonde and she claimed she had a tattoo which read "carpe diem" just below her bikini line.

Natrually enough, I asked her if the "carpe" matched the curtains, which I thought was hilarious.....she didn`t!

EVERYTHING is Bush`s doing. Didn`t you know that? LOL

duffytoler had it right. Notice the "m" term vanishes, indicating escape velocity is dependent on the mass of the planet, not the mass of the spacecraft or projectile. Fun fact for the evening, I suppose.

AYE!

It defines the relative speed of two bodies attracted toward each others by heir gravity.

So in this context the formula means:

If you can read this you`re too close you dumbass

well the left part of the equation is the gravitational energy it takes to get from 0 to radius R with an object of mass mx away from the mass M. This is the integrated gravitational force -G_x (m_x M)/r^2 from 0 to R. I guess they made a mistake here, because you normally don`t start at 0 but rather at a point with the radius of the mass m (for example the radius of the earth). Although a little extra energy won`t hurt when escaping the Earths pull, I guess that if NASA can`t do any better in math we don`t have to wonder when the space ships crash...

On the other side we have the kinetic Energy of the mass mx, thus by equating these two energies we get the escape velocity V_ESC it takes the Object of mass mx to escape the gravitational pull to mass M.

I`m an electrical engineer so this really is not my field, so you can keep any errors :-D.

That joke never gets old.

Year 12 Astrophysics right there.

It`s called "phase shifting" and it`s totally physically true. You`d just have to be going extremely fast.

Also V(esc)^2 looks like their squaring the subscript and not the parameter itself.

The "x" is "times"

Natrually enough, I asked her if the "carpe" matched the curtains, which I thought was hilarious.....she didn`t!"

Hahahaha! Although most might say that`s a fail, my inner nerd says this is a WIN.

Oh and all US government facilities buy American cars. Which includes the Pontiac GT. At LLNL and LBNL, the directorate usually drive Chrysler 300`s and Cadillac STS`s. My car was a Ford Crown Vic P71. And those are your tax dollars at work, folks!

> Hi, well the left part of the equation is the gravitational energy it takes to get from 0 to radius R with an object of mass mx away from the mass M. This is the integrated gravitational force -G_x (m_x M)/r^2 from 0 to R...

Your IQ is too high for i-am-bored. Perhaps you`d be happier over at 4chan...

Nah only kidding dude.

So basically, if you add positive kinetic energy (i.e. speed away from the planet) to your gravitational potential energy, it eventually becomes 0, and you escape the gravity well. The speed necessary for this is escape velocity.

So, since you`re saying:

gravitational potential energy + kinetic energy = 0

You are really saying:

-gravitational potential energy = kinetic energy

And therefore, you substitute in 1/2mv^2 for kinetic energy and GmM/R for gravitational potential energy, and end up with a wonderful equation for calculating escape velocity on any given planet.

Rocket science isn`t difficult. There`s minimal friction, predictable behaviors, and a lot of it can be solved through energy equations and a minimum of calculus. No air to worry about, or kinetic friction, or rotational inertia, just objects in space.

Rocket engineering on the other hand is a godawful nightmare I do not want anything to do with.

> Rocket science isn`t difficult. No air to worry about, or kinetic friction, or rotational inertia, just objects in space

On the other hand, EVERY atom in the universe exerts a gravitational force upon every OTHER atom in the universe, which would tend to make it a little more difficult if they didn`t just cheat and discount 99.9999999% of them as being `too weak to bother with`.

delta v = SUM u*Ln(Mi/Mf) - g*t*Cos(theta)

I is smaller than 3, the function of modulus 5 x

It`s called "phase shifting" and it`s totally physically true. You`d just have to be going extremely fast."

@nerdtchn: I know phase shifting and I get red shift/blue shift... obviously better than you. Red wouldn`t turn blue, it would shift blue. It would become a slightly oranger color of red.

The other side of the equation seems to contain the mass of 1 body and its velocity, so i would assume this equation is what u need to solve in order to put a satelite in a stable orbit around the earth, or maybe to calculate wich distances from the earth can be used as stable orbits for satelites.

or something like that :D

Gx^2mM/R (that is x squared