Timeline for Maximum speed of a rocket with a potential of relativistic speeds
Current License: CC BY-SA 3.0
14 events
| when toggle format | what | by | license | comment | |
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| Mar 26, 2016 at 14:34 | history | protected | Qmechanic♦ | ||
| Jun 7, 2011 at 12:03 | answer | added | Martin Gales | timeline score: 0 | |
| Jun 3, 2011 at 18:22 | answer | added | Alan Rominger | timeline score: 3 | |
| May 4, 2011 at 0:48 | answer | added | Vintage | timeline score: 0 | |
| May 1, 2011 at 19:28 | answer | added | Zo the Relativist | timeline score: 5 | |
| May 1, 2011 at 17:40 | comment | added | David Z | @John: typically yes, but one can build two rockets of different length but carrying the same amount of fuel and having the same mass, and in that case the difference in length would be irrelevant. So I wouldn't say that the length (directly) affects the maximum speed. On the other hand, a difference in mass or fuel payload will change the maximum speed, even if other factors are fixed. Basically I'm saying that $\partial v_\text{max}/\partial(\text{length}) = 0$, but that is not the case for the other factors. | |
| May 1, 2011 at 17:35 | comment | added | John McAndrew | @David, the length affects the volume and hence the mass of the rocket, as well the amount of fuel it can carry. I'd say all 4 affect the maximum speed. | |
| May 1, 2011 at 17:13 | history | edited | user1355 | CC BY-SA 3.0 |
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| May 1, 2011 at 16:23 | comment | added | David Z | A rocket which ejects its exhaust faster will acquire more momentum per unit of fuel, and a rocket which is less massive (not counting the fuel to be used) will move faster for a given amount of momentum. This should make sense intuitively but it's backed up by the "rocket equation" $v(t) = v(0) + v_\text{exhaust}\ln\frac{m(0)}{m(t)}$ which can be derived from the law of momentum conservation. Notice that both the exhaust speed and the rocket mass enter the equation. | |
| May 1, 2011 at 16:19 | history | edited | Phillip Wang | CC BY-SA 3.0 |
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| May 1, 2011 at 16:08 | comment | added | Phillip Wang | @David: It's a multiple-choice question from an exam we've already taken. In what way would option b) and c) affect the rocket's maximum speed? | |
| May 1, 2011 at 16:08 | answer | added | user1355 | timeline score: 1 | |
| May 1, 2011 at 16:02 | comment | added | David Z | Where did that quote come from? It doesn't look like a multiple choice question, since all of those factors except the length affect the rocket's speed. | |
| May 1, 2011 at 15:52 | history | asked | Phillip Wang | CC BY-SA 3.0 |