<p>Obviously, some of you guys have never studied relativity...or at least not correctly anyway.</p>
<p>If one object is traveling at speed x and the other is traveling at speed y in the other direction, then the velocity of one with reference to the other, is:</p>
<p>v = (x + y)/(1 + (xy/c^2))</p>
<p>So even if the two objects were traveling at speed c, the speed of one with regard to the other would be:</p>
<p>v = (c + c)/(1 + (c*c/c^2))
v = 2c/(1 + c^2/c^2)
v = 2c/2
v = c</p>
<p>I'm guessing that most of you are thinking something like this: nothing can transcend the speed of light, but if they are moving with respect to one another, it can SEEM like one is traveling faster than c, even though it's not. What's the problem with this? Because you (and this is pretty normal, so don't fret) are stuck in the Newtonian idea that absolute motion exists. This is wrong! It doesn't. If you are walking away from school, it is just as right to say that the school is moving away from you.</p>
<p>No, in fact, I proved (mathematically) your comment that if two objects are travelling at c, they observe one another travelling at c. It's directed at the multitudes of people in this 11-page thread who have gotten the problem wrong.</p>
<p>I'm hoping that one emphatic statement will get people to finally stop repeating the same error again and again in this thread. :)</p>
<p>But the two objects AREN'T travelling at c. They are both travelling at .60c in the opposite direction. Therefore, the observed speed should be greater than .60c but not exceed c. At least I hope so.</p>
<p>It is c, because they are observing each other, eg. light, and light travels at c no matter how fast you go, therefore, the answer is c, but i put 0.6c < x < c</p>
<p>The answer to the question with the blob asking where the electric field strength is greatest was not D, but C; electric field line density is strongest where the curvature of the surface of the object is greatest. At point C, the curvature of the surface was most pronounced.</p>
<p>its the point that was directly between the + and - charge, and located above them.</p>
<p>This is correct because.. if you look at electric field lines, charges make a semielliptical shape flowing btw + and -.... only 1/2 way between the two is where a charge would feel a force directly east/west</p>
<p>ok the answer to the WEST question is definitely C (good job bsbllallstr8 with the diagram)</p>
<p>BUT does everyone agree with these two other questions:</p>
<p>1) spaceships question: the answer was c, and NOT .6<v<c</p>
<p>2) the blob question #74 was the tip of the blob (to the right of the diagram)</p>
<p>Neuhaus said: The answer to the question with the blob asking where the electric field strength is greatest was not D, but C; electric field line density is strongest where the curvature of the surface of the object is greatest. At point C, the curvature of the surface was most pronounced. </p>
<p>do you mean at the tip, where the curvature is greatest?</p>
<p>i dont understand the electric field line question... it didnt say that those were electric field lines anyway.. it just said that it was a blob, isnt electric charged stronger the closer you get to the center of the object?</p>
<p>74 was crap... i dont know... i guess there really is no point to try to figure these out except for future tests... lol.... i just hope i didnt screw up more than 9questions :) out of the 74 that i did hahaha</p>
<p>
[quote]
But the two objects AREN'T travelling at c. They are both travelling at .60c in the opposite direction. Therefore, the observed speed should be greater than .60c but not exceed c. At least I hope so.
[/quote]
</p>
<p>No. It's not possible, at least, the most recent physics hasn't yet proven that travelling with the same speed as that of light is possible for a non-massless object. It's above .6c, but below c. As someone has mentioned before, we got to use this formula to solve this problem:</p>
<p>v = (x + y)/(1 + (xy/c^2))</p>
<p>Let's pick the ship that moves to the left as the stationary frame of reference. Call it ship 1. For it, earth moves to the right at the speed of .6c, and the other ship (ship 2) moves to the right as well at certain speed v. According to the classical Newtonian (or was it Galilean?) mechanics, all you have to is add the speed of the earth with respect to ship 1, and the speed of ship 2 to earth (which if .6c) to get the relative speed of ship 2 with respect to ship 1. </p>
<p>We would then have .6c + .6c = 1.2c. Einstein postulated that nothing can move faster than light, and nothing that has mass can move as fast as light can -was it the consequence? I don't remember the exact word of his postulate BTW-. With that said, the speed of ship 2 with respect to ship 2 can't possibly be 1.2c, or even c, which means that, we can't use that formula to find the relative speed of ship 2 wrt ship 1. </p>
<p>By plugging in all of those numbers into the formula COnker posted in his previous post, we will get the more accurate answer. That said, the relative speed of ship 2 with respect to ship 1 is:</p>
<p>.6c + .6c / [1+(.6c*.6c)/c^2] = 1.2c / 1.36 which is less than c, but greater than .6c (~.89c or something like that).</p>