Someone Posted May 7, 2016 Report Share Posted May 7, 2016 Just now, iblearner said: I did the same thing, but didn't arrive at the answer they wanted. I got to the answer they wanted. Did you take the Albedo into account? How did you find the electricity question? Reply Link to post Share on other sites More sharing options...
Someone Posted May 7, 2016 Report Share Posted May 7, 2016 9 minutes ago, Haitham Wahid said: For the four slit experiment, they asked you to deduce the wavelength of light from the graph. To do that you would need to look for the section on the graph for which the first minimum of the single slit diffraction pattern modulate the 4 slit interference pattern. As far I as I remember, that min point occurred at θ ≈ 0.45. Now what you do is to use the formula θ = λ/d. The gave you d = 10^-6. Thus you just substitute to get λ 4.5*10^-7m and you got the answer. Ooops, yeah I was being stupid. It doesn't matter any more. I will study for paper 3 now so that I will be more prepared on Monday. Reply Link to post Share on other sites More sharing options...
Guest iblearner Posted May 7, 2016 Report Share Posted May 7, 2016 26 minutes ago, Someone said: I got to the answer they wanted. Did you take the Albedo into account? How did you find the electricity question? The electricity question i used Kirchoff's Law. I got an answer. What bout you? Reply Link to post Share on other sites More sharing options...
Sandy Posted May 7, 2016 Report Share Posted May 7, 2016 1 minute ago, iblearner said: The electricity question i used Kirchoff's Law. I got an answer. What bout you? I did the same. What answer did you get? Reply Link to post Share on other sites More sharing options...
Guest iblearner Posted May 7, 2016 Report Share Posted May 7, 2016 4 minutes ago, Sandy said: I did the same. What answer did you get? 2V i think i forget Reply Link to post Share on other sites More sharing options...
Sandy Posted May 7, 2016 Report Share Posted May 7, 2016 17 minutes ago, iblearner said: 2V i think i forget oh, I got 8V. A few people from my class as well. While others got 14V. Not sure what's the correct answer now. I'm even more confused Reply Link to post Share on other sites More sharing options...
Guest iblearner Posted May 7, 2016 Report Share Posted May 7, 2016 5 minutes ago, Sandy said: oh, I got 8V. A few people from my class as well. While others got 14V. Not sure what's the correct answer now. I'm even more confused I don't remember what i got. i vaguely remember getting a 2, but idk. Reply Link to post Share on other sites More sharing options...
Guest SNJERIN Posted May 7, 2016 Report Share Posted May 7, 2016 14 minutes ago, Sandy said: oh, I got 8V. A few people from my class as well. While others got 14V. Not sure what's the correct answer now. I'm even more confused I got 8V as well !! Reply Link to post Share on other sites More sharing options...
SD98 Posted May 7, 2016 Report Share Posted May 7, 2016 3 minutes ago, Haitham Wahid said: I got 8V as well !! 8V too! Reply Link to post Share on other sites More sharing options...
kevG Posted May 7, 2016 Report Share Posted May 7, 2016 1 minute ago, Haitham Wahid said: I got 8V as well !! I got 8V as well, but it was only a 2 point question. Should've been at least 4 and I spent way more time than for that 2 point question What did you guys get for the escape velocity 3/4 question? I got 9/16R, I don't know if it's right but I was in such a hurry to finish it that I didn't check... I used v^2 = u^2 + 2as to find s Reply Link to post Share on other sites More sharing options...
NickyJo Posted May 7, 2016 Report Share Posted May 7, 2016 20 minutes ago, Sandy said: oh, I got 8V. A few people from my class as well. While others got 14V. Not sure what's the correct answer now. I'm even more confused I got 14V. but I feel like that's the wrong answer. Reply Link to post Share on other sites More sharing options...
danishsiddiquie Posted May 7, 2016 Report Share Posted May 7, 2016 I got 14V aswell! Reply Link to post Share on other sites More sharing options...
Guest SNJERIN Posted May 7, 2016 Report Share Posted May 7, 2016 (edited) 7 minutes ago, kevG said: I got 8V as well, but it was only a 2 point question. Should've been at least 4 and I spent way more time than for that 2 point question What did you guys get for the escape velocity 3/4 question? I got 9/16R, I don't know if it's right but I was in such a hurry to finish it that I didn't check... I used v^2 = u^2 + 2as to find s I think for the maximum height that the shuttle could reach I found to be equal to 9/7R. But why did you use this equation. As far as I know this is only valid for uniform acceleration but in our case it wasn't. Instead I considered energy conservation. That is to say, I calculated the total energy of the shuttle at the surface of the planet and equated it to the total energy at the maximum height. I don't know really, Edited May 7, 2016 by Haitham Wahid Reply Link to post Share on other sites More sharing options...
kevG Posted May 7, 2016 Report Share Posted May 7, 2016 (edited) 16 minutes ago, Haitham Wahid said: I think for the maximum height that the shuttle could reach I found to be equal to 9/7R. But why did you use this equation. As far as I know this is only valid for uniform acceleration but in our case it wasn't. Instead I considered energy conservation. That is to say, I calculated the total energy of the shuttle at the surface of the planet and equated to the total energy at the maximum height. I don't know really, You might be right but I don't really know cause the people on reddit had many different answers, some people got 16/9 R, some got 9/16R, and many also got 9/7 and 7/8... I assumed that acceleration was uniform in this case and velocity would be 0 when s is as max, kinda like projectile motion cause the shuttle would not have been able to leave the atmosphere with 3/4 escape velocity required... Anyways, what about the 4 point question asking for the latent heat of ice? I got around 30000 J/Kg, I hope that's right cause atm I'm crushed Edited May 7, 2016 by kevG Reply Link to post Share on other sites More sharing options...
danishsiddiquie Posted May 7, 2016 Report Share Posted May 7, 2016 4 minutes ago, kevG said: You might be right but I don't really know cause the people on reddit had many different answers, some people got 16/9 R, some got 9/16R, and many also got 9/7 and 7/8... I assumed that acceleration was uniform in this case and velocity would be 0 when s is as max, kinda like projectile motion cause the shuttle would not have been able to leave the atmosphere with 3/4 escape velocity required... Anyways, what about the question with the 4 point question asking for the latent heat of ice? I got around 30000 J/Kg, I hope that's right cause atm I'm crushed You're right, I think I got the same answer Reply Link to post Share on other sites More sharing options...
Guest SNJERIN Posted May 7, 2016 Report Share Posted May 7, 2016 4 minutes ago, kevG said: You might be right but I don't really know cause the people on reddit had many different answers, some people got 16/9 R, some got 9/16R, and many also got 9/7 and 7/8... I assumed that acceleration was uniform in this case and velocity would be 0 when s is as max, kinda like projectile motion cause the shuttle would not have been able to leave the atmosphere with 3/4 escape velocity required... Anyways, what about the question with the 4 point question asking for the latent heat of ice? I got around 30000 J/Kg, I hope that's right cause atm I'm crushed Oh I see. I feel like encountering a similar problem of a space shuttle being launched with a velocity that is a fraction of the escape speed before so the only approach I could think about was energy conservation. For the latent heat I think I got a similar value, though I don't remember exactly what I got. Reply Link to post Share on other sites More sharing options...
kevG Posted May 7, 2016 Report Share Posted May 7, 2016 8 minutes ago, Haitham Wahid said: Oh I see. I feel like encountering a similar problem of a space shuttle being launched with a velocity that is a fraction of the escape speed before so the only approach I could think about was energy conservation. For the latent heat I think I got a similar value, though I don't remember exactly what I got. for the first question about the ice, did you get the velocity at A as 5 m/s? tbh I only felt confident about that q Reply Link to post Share on other sites More sharing options...
Guest SNJERIN Posted May 7, 2016 Report Share Posted May 7, 2016 2 minutes ago, kevG said: for the first question about the ice, did you get the velocity at A as 5 m/s? tbh I only felt confident about that q Yep, that's correct! What about the question in which they asked whether crushed Ice would melt faster than the block of the ice. That question was totally unexpected. However, intuitively I imagined that crushed ice will melt faster. what did you answer to this. Reply Link to post Share on other sites More sharing options...
Comrade Posted May 7, 2016 Report Share Posted May 7, 2016 Just now, Haitham Wahid said: Yep, that's correct! What about the question in which they asked whether crushed Ice would melt faster than the block of the ice. That question was totally unexpected. However, intuitively I imagined that crushed ice will melt faster. what did you answer to this. I answered that as well because I figured that it would take less energy to break the bonds of ice that's already been roughed up. No idea if that's correct, however. Reply Link to post Share on other sites More sharing options...
Sandy Posted May 7, 2016 Report Share Posted May 7, 2016 2 minutes ago, Haitham Wahid said: Yep, that's correct! What about the question in which they asked whether crushed Ice would melt faster than the block of the ice. That question was totally unexpected. However, intuitively I imagined that crushed ice will melt faster. what did you answer to this. which timezone did you have? Reply Link to post Share on other sites More sharing options...
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