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    (Original post by tangotangopapa2)






    Thank you for the reply. Yes, the answer is the same. :yes: Average density of cloud is less than that of air. Small droplets so large surface area so high viscous drag so they tend to be floating forever in the same way as does the dust particle in air.

    The question comes from the book called " Physics Olympiad: Basic to Advanced" which I downloaded yesterday.

    Edit: the name of the book is " Physics Olympiad: Basic to Advanced Exercises"

    following are the exact statements from the book.

    Attachment 577264Attachment 577264577266
    Nice! haha i just leaned why dust particles float
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    (Original post by tangotangopapa2)






    Thank you for the reply. Yes, the answer is the same. :yes: Average density of cloud is less than that of air. Small droplets so large surface area so high viscous drag so they tend to be floating forever in the same way as does the dust particle in air.

    The question comes from the book called " Physics Olympiad: Basic to Advanced" which I downloaded yesterday.

    Edit: the name of the book is " Physics Olympiad: Basic to Advanced Exercises"

    following are the exact statements from the book.

    Attachment 577264Attachment 577264577266
    Sorry but you seem to be extremely well prepared especially in terms of the Olympiads, are you by any chance doing them or have done them?
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    (Original post by Ipsooo)
    Sorry but you seem to be extremely well prepared especially in terms of the Olympiads, are you by any chance doing them or have done them?
    Thanks. I might be doing Olympiads if I get a chance.
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    We only need to learn the top half of this table for PAT and interview, right? (not cot, sec or cosec)

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    (Original post by m3racer123)
    We only need to learn the top half of this table for PAT and interview, right? (not cot, sec or cosec)

    Yup.

    The syllabus says:

    "Knowledge of the values of sin, cos and tan for angles of 0, 30, 45, 60 and 90 degrees (and angles offset from these by multiples of 90 degrees) may be assumed."
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    (Original post by hellomynameisr)
    Yup.

    The syllabus says:

    "Knowledge of the values of sin, cos and tan for angles of 0, 30, 45, 60 and 90 degrees (and angles offset from these by multiples of 90 degrees) may be assumed."
    What does the angles offset mean?
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    (Original post by NatoHeadshot)
    What does the angles offset mean?
    I think it just means the angles that can come from these standard values. So 135, 180, 270 and 360 etc
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    Which papers would you guys recommend that I should do from the physics olympiad ones? Are the AS ones alright or should I look into the A2 ones too?
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    (Original post by don't cry-craft)
    Which papers would you guys recommend that I should do from the physics olympiad ones? Are the AS ones alright or should I look into the A2 ones too?
    How about you try an AS and an A2 and a round 1 and you rank them from hardest to easiest and do the middle one. I have to say though that round 1 has short questions which resemble the pat( old papers )
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    Guys where would we have to choose if we want an open college or if we want to pick a Uni? I don't see that option on ucas?
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    (Original post by NatoHeadshot)
    Guys where would we have to choose if we want an open college or if we want to pick a Uni? I don't see that option on ucas?
    I'll repeat this in case anyone here was wondering: when you put your uni choices in there's also a campus code, each college has a different one for Oxford.
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    (Original post by tangotangopapa2)
    Thanks for the inspiration mate. Good luck to you too.



    Studying elementary machines more thoroughly is a good idea. You could be more cautious about this when you see more numbers of wire.
    Just a quick question for you to check the concept.

    You have a mass attached to a pulley. A rope passes through that pulley and suspends the pulley. The two sides of rope are vertical.

    - To the left of the pulley rope is released at the rate of 3 m/s and to the right the rope is pulled at the speed of 12 m/s.

    Find with what speed and in what direction does the mass move.
    Is the ans up by 9?
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    (Original post by NatoHeadshot)
    Is the ans up by 9?
    No the answer is up by 4.5 . Same concept here. You need to divide by 2 because there are 2 ropes.
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    (Original post by tangotangopapa2)
    No the answer is up by 4.5 . Same concept here. You need to divide by 2 because there are 2 ropes.
    I'm not really following I'm sorry /:
    You said one rope goes down by three and another is pulled up by 12 I think? So what our saying each rope is giving 4.5? /:

    Could you draw the scenario out for me
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    Np !

    I am referring to the problems like this:
    Name:  pulley rope puzzle..png
Views: 163
Size:  56.4 KB
    See page 13, post 253 and 254 of this thread for details.




    (Original post by NatoHeadshot)
    I'm not really following I'm sorry /:
    You said one rope goes down by three and another is pulled up by 12 I think? So what our saying each rope is giving 4.5? /:

    Could you draw the scenario out for me
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    (Original post by tangotangopapa2)
    Np !

    I am referring to the problems like this:
    Name:  pulley rope puzzle..png
Views: 163
Size:  56.4 KB
    See page 13, post 253 and 254 of this thread for details.
    Hey!

    Are there any resources for learning and practicing such pulley system problems? Especially multiple pulley systems of different diameters (quite bad that these :P).
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    (Original post by kj5576)
    Hey!

    Are there any resources for learning and practicing such pulley system problems? Especially multiple pulley systems of different diameters (quite bad that these :P).
    Engineering Mechanics: Statics by Hibbeler Chapter 6.6 Frames and machines is quite comprehensive

    In fact the entire chapter on Structrual Analysis is useful, alongside fluid pressure.
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    Hey, how have people started their preparation?? I don't even know where to begin!
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    Hi guys do we need to know the compound angle formulas? Thanks
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    (Original post by A.K57)
    Hi guys do we need to know the compound angle formulas? Thanks
    No. I guess you could memorise double angle formula just in case. but strictly speaking you won't be needing them
 
 
 
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