Recent content by Dgonzo15

OK, so the formula E^2=P^2... reduces to E=pc for photons since photons have zero REST mass. Since they have zero REST mass, what is their mass when they are moving at c? You would need to know their mass in order to calculate p so you can calculate E when they are moving, right?

So how would I calculate the energy of a photon? Since a photon travels at c, gamma (in E=γmc^2) would be undefined, so it doesn't make any sense to calculate the energy of a photon. Also, are photons considered to have mass, because mass is also a factor in E=γmc^2.

Energy is E=γmc^2, but when I calculate this, will my result be in joules? I am unsure what the units are when I calculate it, and I keep hearing people saying joules. Also, what is PJ and MJ?

The first four subshells have one s sublevel, then s and p, then s, p, and d, and then s, p, d, and f, respectively. Where does the 5s go? Does it go in the fifth atomic shell? If that's the case, where does the 7th s sublevel go? From my understanding, the 7th s sublevel would go in the 7th...

I just got unit work of light and mass, and know NOTHING about it, and the site has no resource links. Can someone please tell me a general idea of what there is to know about light and mass, formulas, or any resources I can use? Also, how would you calculate the 'energy' of a photon, such...

Homework Statement Persons A and B are rowing boats due east. B at .5c, and A at .7c, both relative to the earth, and are in parallel tracks 3 light seconds apart (B is north of A). A starts out behind B, but as A passes B, A throws a stopwatch straight up at .5c in A's reference frame. B...

So what if I'm driving on the road in a car near the speed of light? I can't see how the road would contract, since, eventually, the car itself would have to contract in width in order to fit within the boundaries of the road; and I believe that I would not experience myself contracting in my...

If an object were to approach the speed of light, its length, as measured by an observer, would become shorter and shorter. But what about the view of the speeding object? If the object is approaching the speed light, then would the world surrounding it appear to be shorter as well? I say...

What exactly is center of mass, and how do I calculate in three dimensions? Also, I need to know how to calculate it in three dimensions at relativistically high speeds? Also, what do they mean by 'center of mass frame', as in the question "What are the energy and momentum in the center of...

Hello, can someone give me an explanation of the time dilation equation t=t(p)*γ? I know it's used to measure something about a difference in sense of time in different reference frames, but I don't know how to put it into context. Can someone give me an example where you would use the time...

Homework Statement I came across this problem in a worksheet and I am completely lost as to where to start; can someone help? The question is: Two trains are heading at the same speed, relative to the Earth, in opposite directions. A bomb explodes on each train, but not at the same times...

Hello all, I've been having trouble with this problem; can someone please help? The problem is: If a light beam is shot parallel to me, and I'm running at .7c in the same direction of the light, how much time passes in the light's reference frame (point of view) if I experienced (Earth's...

From what I know, v is the speed of the reference frame which the light is on--is this what you meant?

Hello, I've recently come across the equation for time dilation, which is t=t(p)*γ, which is t=t(p)*(1/√(v^2/c^2)). Can someone please clarify what each of these variables mean?