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General Thoughts: Physics (4 Viewers)

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cyradis

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Oh no! I mixed up photocell with solar cell asjhjfkhdakjf failllll
does anyone know how many marks i could get? :(
 
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studybuddy101

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It's 51.91 to two dp. Use centripetal acceleration and set it to 1g (9.8). Radius is 550/2
 
iBibah

iBibah

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Fizzy_Cyst said:
Q2Q was simple.
Interesting that all the big core questions came from Ideas.
Not very many hard qs, a couple of tricky MC though
Click to expand...
My answers in Q2Q were quite mediocre, never really mastered it (though i do think i pumped the de Broglie question)
 
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yasminee96

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There were many questions that required manipulation of topics. The long responses were good, but many students in the state, if not majority, would not have gotten the torque question with the weight on the end of the motor, or the centripetal force question (part a and b), and there were many tricks in the m/c. The emf graph would've put a lot of people off as well, any guarantee the long responses will be marked harsh (as per usual). It's super easy to make silly mistakes with almost half the paper being calculations.

Doubt the cut off will be any higher than last year. It may have been easier for most people on this site, but it was definitely different for others. Cut off will either be same or lower IMO
 
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superSAIyan2

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I got 51.91 but not sure why g is 9.8. Is the space station being tested on earth
 
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pls

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I got rotational velocity = 73.4m/s. I equated f=ma with f=mv^2/r. You get v = √ (ar). Sub in a as 9.8 and r as the radius as 550.
 
panda15

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pls said:
I got rotational velocity = 73.4m/s. I equated f=ma with f=mv^2/r. You get v = √ (ar). Sub in a as 9.8 and r as the radius as 550.
Click to expand...
Diameter is 550, r is 275. Bored of Studies are just being pricks.
 
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pls

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+1 to the silly error count. What about the motor with the mass attached. Im not sure i got that. Did you say f=w=mg which is 0.49 N or something like that? Then for the next bit find torque using t=fd (with f from the previous question and d= radius of the shaft or whatever that was) and equate that with t=nbIAcosø to find current?
 
panda15

panda15

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pls said:
+1 to the silly error count. What about the motor with the mass attached. Im not sure i got that. Did you say f=w=mg which is 0.49 N or something like that? Then for the next bit find torque using t=fd (with f from the previous question and d= radius of the shaft or whatever that was) and equate that with t=nbIAcosø to find current?
Click to expand...
Yeah, I got about 0.163 I think.
 
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studybuddy101

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pls said:
+1 to the silly error count. What about the motor with the mass attached. Im not sure i got that. Did you say f=w=mg which is 0.49 N or something like that? Then for the next bit find torque using t=fd (with f from the previous question and d= radius of the shaft or whatever that was) and equate that with t=nbIAcosø to find current?
Click to expand...
Yeah that's what I did. From memory 0.16 amps
 
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