| User | Post |
Teundusia
Posts: 152/760 |
erm...
"define x,y and z as massive objects..."
i know nothing about the answer but i do know that in 1 dimensions ALL objects are the same size. the is no MASSIVE about it |
NSNick
Posts: 1680/3875 |
Well, the formula is with addition, but one of them is negative, so yeah. |
blackhole89
Posts: 513/971 |
.9944751381215469613259668508287292817679558011049723756906077348066298342541436464088397790055248619...c
The corresponding formula is:
v=(v1-v2)/(1-v1v2/c2).
There was a neat illustration of this stuff in a recent Spektrum der Wissenschaft (a local scientific magazine) release, but I can't seem to find it now. Anyway, it said that unidirectional movement still is two-dimensional in some way, with the dimensions being distance and time. The faster an object becomes, the less it moves on the "distance" and the more on the "time" axis. Or something like that.
Hope this helps~ |
Zem
Posts: 584/1107 |
Originally posted by Grey
I'm not sure if I'm thinking in the right terms, anyway. I was thinking about stuff like when two cars are going toward each other at 60 MPH the speed of one car from the point of view of the other car is actually 120 miles per hour... That kind of stuff... It's not relevant here, I guess.
Right, that works for low speeds but when you get close to c, it changes because objects never appear to be moving at or above c at any frame of reference. |
Grey the Stampede
Posts: 1573/3770 |
But frame of reference would dictate that the speed of an object in one object's frame of reference is based on the speed of the object being referred to...
I'm not sure if I'm thinking in the right terms, anyway. I was thinking about stuff like when two cars are going toward each other at 60 MPH the speed of one car from the point of view of the other car is actually 120 miles per hour... That kind of stuff... It's not relevant here, I guess. |
||bass
Posts: 178/817 |
It doesn't matter if Z is moving. X, Y, and Z are the only objects in this theoretical system, therefore X, Y, and Z can only be moving relative to each other. There is no such thing as absoloute velocity. |
Grey the Stampede
Posts: 1571/3770 |
Right, right, I'm thinking in terms of scalar quantities. 
Is Z moving, too? |
||bass
Posts: 177/817 |
Grey's answer is definately wrong. 1.8c or -1.8c was the ONLY answer that I am 100% sure is definately incorrect.
Iggy's answer, as far as I can tell. Is either correct, or very close to correct. |
Iggy Koopa
Posts: 213/214 |
.994475138122c.
(Thanks goes out to CHz for that answer.) |
Grey the Stampede
Posts: 1570/3770 |
Negative 1.8C.
Velocity is a vector quantity, which means it needs a direction, though... In the case of Y, X would be traveling negatively. And since the rules of Point of reference dictate that an object's speed doubles when it travels in the opposite direction of a moving object, it's ok for the object's speed to go over the speed of light, since point of reference doesn't dictate actual velocity, just percieved velocity. |
||bass
Posts: 176/817 |
Define c as velocity 299 792 458 m / s
Define x, y, and z as massive objects traveling on a 1 dimensional line.
On this line, x is moving at .9c right relative to z.
Y is moving at .9c left relative to z.
What is the velocity of x relative to y, keeping in mind that it is not possible for relative velocities of massive objects to equal or exceed c? |
