Help needed with physics

wishboy SG · 2008-01-15T20:56:12+00:00

EDIT: ok i saw the above post after i replied ok thanks alot!

wishboy SG

1.
What happens when the Sun no longer have gravitational force, as in the force that pulls the 8 planets? And why?

2.
On the table there are alot of small pieces of paper.
When you rub a ruler until it's hot, and put the ruler near the pieces of paper, why some paper will stick onto the ruler, and some paper will just like get moved a bit?

TIA! Very Happy

unclebutcher SG

1. got 2 competing theories i believe. one is that, instantly, the earth and the 8 planets go off on a tangent. newtons theory

however, if you think about it, since light from sun goes to earth in 8 mins, and nothing is faster than light, if the sun disappears, wouldnt it take 8 mins before the earth dislodges from the circular motion? einstein's theory.

2. static electricity

wishboy SG

thanks Very Happy

err... but y the planets will go off in random directions?

tut4nkh4m3n SG

random meh? orbit what

Darkness_hacker99 SG

orbit is when there's Sun gravitation pull mah..

I think without the sun, it'll go out of orbit and travel is a curve like those you see in soccer.

unclebutcher SG

no it will go off in a tangent to its original path. e.g.

at the point where the sun stops pulling on earth, the planet will go off on a straight line

wishboy SG

EDIT: ok i saw the above post after i replied Embarassed

ok thanks alot! Very Happy

Darkness_hacker99 SG

Ah uncle.. Do you mind I clarify something with you?

If the Sun disappears at an instance, because the Earth is still (self)spinning at the point where the gravitational effect is gone. Because the presence the spinning motion of the Earth, it'll not go straight. Like I say, I think it'll be like a ball traveling in a curve (not straight).

SBS3625D SG

You is talking the Banana effect? The Banana effect only applies in FLUIDS.

Space is vaccum.

eagle SG

I believe you are referring to projectile motion. It does not matter whether it is fluid or vaccum. It happens on earth because of the earth's gravitational pull. If there's no external force on the object, it will continue to move in the tangent at the point where the force is lost.

Uncle, the Einstein's theory is interesting. Have to admit didn't read that before, but makes sense that it comes from the originator of relativity.

ultranova3 SG

Watch this to understand more about the space-time curvature
http://www.youtube.com/watch?v=0rocNtnD-yI&feature=related

SBS3625D SG

Yah, but if there's no external force and the earth is spinning, then the path will not be curved.

In that case, then the medium we have to take into account.