Author Topic: Question about gravity and mass (Read 1780 times)

NUTTZ · « **Reply #30 on:** January 29, 2001, 04:21:00 PM »

I think Fscott should share his "stash"

NUTTZ

Jimdandy · « **Reply #31 on:** January 29, 2001, 04:21:00 PM »

"There are billions and billions of stars..."

Picture a spaceship flying over. You can see thru the spaceship. Inside is a clock that counts by bouncing a laser between to pieces of glass. Now trace the path of the laser as the ship flies over head. Which clock is slower retaliative to the observer on the ground the observers or the spaceships.

There is a train traveling at you. Which direction in the light spectrum is the light on the front of the train shifting toward. Which side of the spectrum is it going to if traveling away from you.

What would happen if the earth stopped rotating. Would we feel a stronger or weaker gravitational pull? What would happen if it spun faster. Would we fly off?

How many licks does it take to get to the tootsie roll center of a tootsie pop.

The last question is the real kicker.

[This message has been edited by Jimdandy (edited 01-29-2001).]

Dux · « **Reply #32 on:** January 29, 2001, 04:23:00 PM »

This is all irrelevant... in the year 1999 the moon is going to be ripped out of Earth's orbit by a nuclear mishap aboard one of our moonbases, and will be sent plummeting through...

huh? 2001?

Never mind.

mrfish · « **Reply #33 on:** January 29, 2001, 04:37:00 PM »

Quote

Originally posted by hitech:
sorry xmab, I beg to differ, there is no force opposing the gravity. The vel of the moon tangentail to it's orbit is just changing the direction that gravity is working on the moon, i.e. the moon is constantly falling and accelerating at the rates you specified it just keeps missing the earth. If the moon was not moving, and could pass threw the earth it would fall and come out the other side at the same hieght it started from. This is in ensence what's going on in an orbit except with it's tang. vel to the earth it's ruberband motion turns into one contiuous arc.

HiTech

not to agree for the sake of agreeing but this is closest to what you would get if you plot it in a force diagram

- the centripetal force (as mentioned previously there is no centrifugal force)produces a vector (again direction and magnitude should be considered not just meshing formulae)which points adjacent to the body's path

- the second vector is of course the attraction due to gravity

conclusion? plot it and add the vectors - the resultant produces what is described above-

hitech · « **Reply #34 on:** January 29, 2001, 04:39:00 PM »

Not so much semantics as just a physical way of looking at things. Math wise for circular orbits it's much easier your way. But now try explaining to some one an extreme elliptical orbit with centrifugal force.

And as to your why hasn't the Vel of the moon changed, I submit it is changing constantly, depends if you view Vel as speed and direction or just speed. I've been doing this simming stuff to long, and it is almost impossible for me to view Vel,And force in any other terms than instantaneous vectors.

I do so love this stuff.
On a side note was debating if a circle is an ellipse, I can't remember if an ellipse definition is 2 unique points or 2 points.

HiTech

[This message has been edited by hitech (edited 01-29-2001).]

Dux · « **Reply #35 on:** January 29, 2001, 04:44:00 PM »

Actually an elliptical orbit is impossible... I think what you mean is a conic section.

Hangtime · « **Reply #36 on:** January 29, 2001, 04:45:00 PM »

Hang sits under a knit apple tree contemplating these postulations.

An apple falls, hits Hang on the head.

Hang rubs the knot on his head.. gets an idea.. loads up AH on the laptop; goes to mission screen and plots a mission to destroy and capture all knit apple trees.

Jimdandy · « **Reply #37 on:** January 29, 2001, 04:54:00 PM »

No one reads my stuff.

Someone answer mine.

I feel so insignificant. I'm a wall flower on the BB of AH.

LOL!

hitech · « **Reply #38 on:** January 29, 2001, 04:54:00 PM »

Ellipse:
http://observe.ivv.nasa.gov/nasa/education/reference/orbits/orbit_sim.html

HiTech

SwampRat · « **Reply #39 on:** January 29, 2001, 05:00:00 PM »

OH MY COD!!...RUN, HIDE!!..WERE ALL GONNA DIE!!
Swamp

xmab · « **Reply #40 on:** January 29, 2001, 05:05:00 PM »

Cool,

Finally a thread that a geek like me can enjoy!

Nice link HT...ellipses are cool

I believe I understand our differences in terms. You probably are thinking in Cartersian coordinates. While I am assuming circular orbit and polar coordinates. If you think in polar or rotational coordinates than the moon's velocity is constant (for a simplified circular orbit and even as a vector). If you think in Cartesian coordinates than the velocity vector's direction is always changing (but not its magnitude).

Ellipitical orbits are certainly more complicated and require one to sum the forces in orthogonal directions to predict the motion.

Aren't you supposed to be working on 1.06? (Hehe).

xmab

mrfish · « **Reply #41 on:** January 29, 2001, 05:09:00 PM »

ok JIMDANDY

since i have already geeked out all day and wasted tons of co. time i think i will take a stab at it:

Picture a spaceship flying over. You can see thru the spaceship. Inside is a clock that counts by bouncing a laser between to pieces of glass. Now trace the path of the laser as the ship flies over head. Which clock is slower retaliative to the observer on the ground the observers or the spaceships.

- the clock on the space ship would seem slow relative to the clock on the ground though each would operate the same in their referential frame (the speed of the spaceship would have been nice)

There is a train traveling at you. Which direction in the light spectrum is the light on the front of the train shifting toward. Which side of the spectrum is it going to if traveling away from you.

- toward the blue end of the spectrum and away the red end

What would happen if the earth stopped rotating. Would we feel a stronger or weaker gravitational pull? What would happen if it spun faster. Would we fly off?

- no gravity has nothing to do with it everything would remian the same (execpt of course weather)
EDIT: oops i meant rotation has nothing to do with it - yes gravity play a small part

How many licks does it take to get to the tootsie roll center of a tootsie pop.

- 22 1/2

[This message has been edited by mrfish (edited 01-29-2001).]

Yeager · « **Reply #42 on:** January 29, 2001, 05:26:00 PM »

Mass is like the stuff somethings made of and gravity is whay happens when you drop stuff!

Yeager

Jimdandy · « **Reply #43 on:** January 29, 2001, 05:32:00 PM »

Ok one more. Which way does the US lunch it's rockets.

A. With the direction of rotation of the earth and why.

B. Against the direction of rotation and why.

C. None of the above and why.

Does a flash light generate thrust. Yes or no and why.

BTW mrfish you think your sooooooooo smart! The tootsie roll one is WRONG WRONG WRONG mister! It should be... (drum roll) The world may never know! So there.

Grumble grumble smart ass... grumble... know it all grumble.

[This message has been edited by Jimdandy (edited 01-29-2001).]

mrfish · « **Reply #44 on:** January 29, 2001, 06:00:00 PM »

yeah yeah jim

with rotation i imagine

Author Topic: Question about gravity and mass (Read 1780 times)

SwampRat