things of interest (1 Viewer)

[MaximusVII]

Say a vehicle is moving at 50km/h and shoots a cannon out at 50km/h we would expect the cannon to have a velocity of 100km/h.
So what about a vehicel moving at .75c and shooting an object of .75c
well it would equal 1.5c, and that would be faster than light.
But it isnt like that at all, vector quantitys are also affected by the constancy of light to make all velocities less than c.
Hence when adding two velocitys:

Velocity= (v1 +v2) / (1 + v1*v2/c*c)

As v approaches c, 1 + v1*v2/c*c becomes significant enough to impact the new velocity hence:

velocity = .96c

Thus all velocitys are less than c.
At least i read this somewhere

 

[serge]

Thus all velocitys are less than c
At least i read this somewhere

A-ha, all evidence points to c being the limiting speed of the universe

 

[Antwan23q]

this is fairly current stuff...

 

[Captain Gh3y]

Say a vehicle is moving at 50km/h and shoots a cannon out at 50km/h we would expect the cannon to have a velocity of 100km/h.
So what about a vehicel moving at .75c and shooting an object of .75c
well it would equal 1.5c, and that would be faster than light.
But it isnt like that at all, vector quantitys are also affected by the constancy of light to make all velocities less than c.
Hence when adding two velocitys:

Velocity= (v1 +v2) / (1 + v1*v2/c*c)

As v approaches c, 1 + v1*v2/c*c becomes significant enough to impact the new velocity hence:

velocity = .96c

Thus all velocitys are less than c.
At least i read this somewhere

So for your example we've got 1.5/(1.5625) = 0.96c.

And if they were both going at .99c, you get .99995c, which implies that, as v --> c, then v + v --> v. This would be due to the object gaining more mass rather than velocity, right?

 

[tpc13]

I suppose the real question you have to ask is: what happens when you're in a car travelling at 0.99c and you turn on the headlights?



EDIT: Note to anyone confused: don't be. Meant as joke, you don't have to worry about this, you won't be asked on it (I hope anyway)...

 

[Bokky]

what happens if ur travelling at 60km/h in a car and u shine a light torche in front of u, will the light travel the speed of light + the speed ur travelling? or will the speed of light still be the same (ie. 300 000m/s)?

 

[Captain Gh3y]

I suppose the real question you have to ask is: what happens when you're in a car travelling at 0.99c and you turn on the headlights?



EDIT: Note to anyone confused: don't be. Meant as joke, you don't have to worry about this, you won't be asked on it (I hope anyway)...

The light will appear to be travelling away from you at 299792458m/s

 

[darkwarrior2]

not to mention that seeing as its v0 / sqrt 1- v2/c2 , if v>c then you'd have negative value and you cant sqrt negative

 

[Bokky]

ohh, so the light still travels at 300 000m/s even tho ur moving? ok, makes more sense, so if ur moving at 100 000m/s in a car and u shine a light, the light moves away from u at 200 000m/s ? GOTCHA

 

[Captain Gh3y]

ohh, so the light still travels at 300 000m/s even tho ur moving? ok, makes more sense, so if ur moving at 100 000m/s in a car and u shine a light, the light moves away from u at 200 000m/s ? GOTCHA

If you're stationary and shine a light, you see the light moving away from you at c relative to yourself.

If you're moving at 100,000m/s in a car and shine a light, you see the light moving away from you at c relative to the car.

If you're moving at (c - 1)m/s and shine a light, you see the light moving away from you at c relative to the car.

 

[Abtari]

isnt it basically this?:

a light beam travels at c from your frame of reference, regardless of your speed... (principle of relativity)

a light beam travels at c for different frames of reference, regardless of their motion. (einstein's principle of special relativity)

someone verify me.

 

[Captain Gh3y]

Yes. 5678910

 

[gogogadgetbrain]

haha.. yes, if your getting confused about the consistency of the speed of light NOW you better get some study done

 

[Abtari]

can someone help me answer this dotpoint:

'discuss the principle of relativity'

i dont know what to include in an answer if they ask such a question

 

[gogogadgetbrain]

principal of relativity

galilean relativity : the laws of mechanics are the same for a body at rest and a body moving with constant velocity

newtonian relativity : it is impossible to do any mechanical experiment, wholly within an inertial frame of reference that can tell you wether the frame is at rest or moving with constant velocity

Poincare - the principal of relativity- the laws of physics are the same for 'fixed' observer as for an observer who has uniform motion of translation relative to him