Recent content by bobbricks

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    Schools Need help choosing universities (UK)

    I have offers from Durham, Imperial, UCL and Manchester but I am struggling to see which one to firm and insurance since they all have their good and bad sides. Manchester (A*A*A): -strong history in physics, with Nobel Prize winners in their staff -in a city so there's lots to do -national...
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    Simple Harmonic Motion Pendulum problem

    Its maximum velocity will be at the lowest point. The total length is 0.3m. Its current vertical height distance from the top is 0.3cos10. So the difference is 0.3-0.3cos10 which is the maximum amplitude..?
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    Simple Harmonic Motion Pendulum problem

    Homework Statement A simple pendulum of length =30.0cm is released from rest from an angle of θ=10.0∘ to the vertical. Assuming that the pendulum undergoes simple harmonic motion, find its maximum speed. Source: https://isaacphysics.org/questions/accuracy_shm_pendulum_num Homework Equations a)...
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    Confused on escape velocity derivation

    That's great thanks (I wasn't shown that in school) :) I thought you could literally equate ½mv²/R (work divided by displacement/radius) to GmM/R² and rearrange for v but it seems it was more involved than I initially thought.
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    Confused on escape velocity derivation

    For derivation, I've been taught to use the kinetic energy formula, calculate work done on moving R, then equate it to the universal law of gravitation formula and end with v=root(2GM/R). Why does using kinetic energy give you the right formula (I.e. why do you do that/what does it show?)...
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    Confused on escape velocity derivation

    I'm confused on how you get the formula v=root(2GM/R²). I know you can use work=forcexdisplacement (W=Fd) so F=W/d. W=½mv² and R=d. Hence, F=½mv²/R Equate that to F=GmM/R² and rearrange to get v=root(2GM/R²). That makes sense as it involves the kinetic energy needed/work done in reaching orbit...
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    Sphere Under Gravity Problem (Isaac Physics)

    I'm stuck on this problem: A small sphere is attached to a fixed point by a string of length =30cm , and whirls round in a vertical circle under the action of gravity at such speed that the tension in the string when the sphere is at its lowest point is three times the tension when the sphere is...
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    Preparing for Cambridge interview- resources/preparation?

    Ah, thanks- although Cambridge don't ask for the PAT (only Oxford do ;) )
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    Preparing for Cambridge interview- resources/preparation?

    So do you think doing the Oxford admission PAT questions would be more useful than doing the Physics Olympiad questions in preparation for a Cambridge interview?
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    Preparing for Cambridge interview- resources/preparation?

    Hi, I'm a UK student who will be applying to the University of Cambridge (England). However, what would be the best preparation I could do for a physics interview if I am invited to one? So far. this is what I've come up with: -Doing Oxford admission PAT tests -Physics Olympiad questions -Past...
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    Solve Cosec x Graph Transformations: Alternative Method without Substitution"

    Question 4b: http://www.skinners-maths.co.uk/specimen%20A%20level%20papers/EC3paper/EC3sh_H.pdf I wrote out that (1)(a+b)=1 and (-5)(a+b)=-1 but that doesn't seem to work? I know you can solve it directly by substituting in the co ordinates from the graph, but is there an alternative to doing...
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    Trig- Sine graph translations question help (C2 A level)

    Hmm..I think I understand thanks- I don't suppose you help me with another question which is similar to this please (question 4b): http://www.skinners-maths.co.uk/specimen%20A%20level%20papers/EC3paper/EC3sh_H.pdf I wrote out that (1)(a+b)=1 and (-5)(a+b)=-1 but that doesn't seem to work? I...
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    Trig- Sine graph translations question help (C2 A level)

    I think I understand but please can you elaborate on why you're starting from 3pi/5 and ending up at pi? (e.g. is it something to do with the function itself, or is there a proof to this?)
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