<p>All three can diffract. I still agree with you basketball1. I’m just wondering if the rocket propulsion refers to the actual pushing off the ground or the keeping up in the air</p>
<p>also which particle has the greatest ratio of charge to mass? Positron…?</p>
<p>propel means a force causing movement. i don’t think it has to do with keeping in the air. Just deals with the first cause of movement.</p>
<p>What did you guys put for the question about a rocket (or something) travelling at 0.9c towards a planet. What would the distance to the planet be as calculated by someone on the rocket.</p>
<p>Answers included “between 0 and D” and “greater than D but smaller than infinity” where D was the distance calculated by someone on earth. I put greater than D smaller than infinity but I think it’s wrong.</p>
<p>Also, I think I misread a question. One of them was asking for the greatest charge:mass ratio. For that I put positron, but I think it might have been asking for mass:charge. Can anyone confirm?</p>
<p>Actually for the rocket, maybe D is right cuz it a conservation of momentum. Although a rocket follows third law, it doesn’t push the ground. It actually pushes the burned fuel…</p>
<p>it was charge to mass…i put positron also</p>
<p>and i think the answer to the rocket at 0.9c was less than d but greater than 0. This is because when objects travel close to the speed of light, length contracts</p>
<p>I was thinking of putting D due to conservation of momentum, but then I didn’t! :(</p>
<p>Thanks basketball1. The boat/rocket question and the relativity one were the main to I was unsure of. Hopefully I haven’t made too many more mistakes…</p>
<p>When you are pushing with a stick while standing on a boat, you have a direct connection with the coast. That is clearly not the case with a rocket 99% of the time (one centimeter in the air? No connection!).</p>
<p>The 0.9c one was smaller than d but greater than zero
I think It was charge mass… I put the one with 1:1 ratio…</p>
<p>also in the wave picture at the beginning of the test, was A the point where the wave was traveling to the top of the page?</p>
<p>Less than D, but greater than zero. To be exact: D sqrt(1 - 0.9^2)</p>
<p>and the rocket one is tough, it really just depends on how it was worded, i just know that rocket propulsion deals with newton’s third law…</p>
<p>yeah what did that wave one mean??</p>
<p>Spaceship problem - spaceship traveling (9/10)c measures the distance to a planet its traveling to vs. the distance we measure to that planet.</p>
<p>I put that the distance measured by the spaceship is shorter. Can anyone verify?</p>
<p>i have no idea, so weirdly worded, i just picked the hightest point, which was A, as the wave traveling to the top of the page</p>
<p>When you travel close to speed of light, length contracts</p>
<p>it is shorter and still greater than 0</p>
<p>I forgot what I put for the wave question… Technically A would be mving down already since it’s the highest… Bad question</p>
<p>I put B. The wave was travelling to the right and the only point which had an upward motion to the left of it was B.</p>
<p>A was at the maximum displacement, meaning that it was about to move down at that instant.</p>