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    Good luck everyone!

    Can I just take this moment to complain how my sibling litera;;y just revised today and went from a C to an A* in a day, it's a p*ss take in my opinion and its unfair to all the people like me who spend so long revising. So basically anything is impossible.
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    (Original post by TheTruthTeller)
    Guys whoever did the p2 2014 paper for practice- what mark did you get?
    I did it for my mocks and I got 52 or 53, cannot remember exactly
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    (Original post by isabellagrace)
    I have not really thought about it; hopefully stars will come up, there was a lot on static electricity in the 2014 paper so I doubt we will be seeing much of that, what do you think?
    I agree with you, though I'm praying for a lot on stars! And nuclear fission / fusion! And lots and lots of equations, just no momentum
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    (Original post by physicsamor)
    Good luck everyone!

    Can I just take this moment to complain how my sibling litera;;y just revised today and went from a C to an A* in a day, it's a p*ss take in my opinion and its unfair to all the people like me who spend so long revising. So basically anything is impossible.
    "Hard work always beats talent."
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    (Original post by TheTruthTeller)
    nice , are you predicted an a star?
    No, I'm predicted a 'b' but my physics teacher is an idiot (and he's our principal🙈) but I'm predicted a* in all other sciences. How are you feeling for tomorrow?
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    I need an A in additional to get to harris Westminster 😩
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    (Original post by AvKar)
    Is this talking about electrical circuits?
    If it is then for a filament bulb at least, the resistance of the bulb increases as the current increases. This is because an increase in current causes the wire in the bulb to heat up, therefore increases the kinetic energy of the ions in the metal wire. As the kinetic energy is greater and the metal ions vibrate more, the electrons (current) cannot pass through the wire as easily as there as more collisions between these electrons and the ions in the wire, hence the resistance increases as the current increases.

    Does this make sense? Don't worry about physics, just try your best!! 💪
    Yes it is and it actually makes so much sense now THANKS SO SO MUCH. Good luck and may you get good grades .... p.s your my lifesaver lol
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    (Original post by MVEMJSUNP)
    On the spec for P2 it says "Candidates should be able to explain resistancechange in terms of ions and electrons."
    but I dont know what it is ... Can someone please explain it to me please!!! Thanks and good luck... for me physics is my worst science anways
    Okay forgive me if I am wrong, but I think resistance increases because as the current is increased, inside a resistor some of the energy is transferred as heat. This temperature rise makes the ions in the resister move faster/vibrate, so the eelectrons cannot pass through it as easily or something so the resistance increases?

    Again, I really am not sure, I HATE electricity
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    (Original post by t.thompson22)
    "Hard work always beats talent."
    XD ssh I was like "well done" but in my head "i want to kill you"
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    (Original post by physicsamor)
    XD ssh I was like "well done" but in my head "i want to kill you"
    Hahah 😂
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    (Original post by MVEMJSUNP)
    Yes it is and it actually makes so much sense now THANKS SO SO MUCH. Good luck and may you get good grades .... p.s your my lifesaver lol
    Hahahahahah you've made my night 😂😂 you toooooo!!
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    My school wants an A to take in A-Level, the pressure is on ;-; (but it doesn't require you to have taken triple XD but you would have to learn the additional unit)
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    (Original post by t.thompson22)
    I agree with you, though I'm praying for a lot on stars! And nuclear fission / fusion! And lots and lots of equations, just no momentum

    Yeah, wow would it not be amazing if the whole of P2 was nuclear physics? I do not really like electricity and all the car stuff too much so hoping not much on that but yeah. P3 hoping stuff on optical fibres and endoscopy comes up, and not much on electromagnetic induction
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    (Original post by Jules12345)
    Can someone please explain regenerative braking please? P2
    I think it is when in a smart car or electric car, when the brakes are applied all the kinetic energy transferred that would have been wasted as heat is converted to electrical then chemical, which is used to charge the cars battery
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    (Original post by AvKar)
    Is this talking about electrical circuits?
    If it is then for a filament bulb at least, the resistance of the bulb increases as the current increases. This is because an increase in current causes the wire in the bulb to heat up, therefore increases the kinetic energy of the ions in the metal wire. As the kinetic energy is greater and the metal ions vibrate more, the electrons (current) cannot pass through the wire as easily as there as more collisions between these electrons and the ions in the wire, hence the resistance increases as the current increases.

    Does this make sense? Don't worry about physics, just try your best!! 💪
    Doesn't the current decrease for the resistance to increase and therefore "the resistance of bulbs increases as the current decreases" o.o wait im wrong aren't I (confused)
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    (Original post by isabellagrace)
    I think it is when in a smart car or electric car, when the brakes are applied all the kinetic energy transferred that would have been wasted as heat is converted to electrical then chemical, which is used to charge the cars battery
    Yep - according to the CGP book:

    "rather than converting the kinetic energy of the vehicle inot heat energy, the brakes put the vehicles motor into reverse. With the motor running backwards the wheels are slowed. At the same time, the motor acts as an electric generator converting kinetic energy into electrical energy that is stored as chemical energy in the vehicle's battery."

    So basically they store the energy of braking rather than wasting it.

    I hope that helps!
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    (Original post by TheTruthTeller)
    Guys whoever did the p2 2014 paper for practice- what mark did you get?
    57 it was a really nice paper : only lost marks on stars which i hadnt revised

    Posted from TSR Mobile
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    (Original post by hannah4475)
    Yep - according to the CGP book:

    "rather than converting the kinetic energy of the vehicle inot heat energy, the brakes put the vehicles motor into reverse. With the motor running backwards the wheels are slowed. At the same time, the motor acts as an electric generator converting kinetic energy into electrical energy that is stored as chemical energy in the vehicle's battery."

    So basically they store the energy of braking rather than wasting it.

    I hope that helps!
    Oh I forgot about the motor in reverse part... Thanks so much!
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    (Original post by Jules12345)
    Can someone please explain regenerative braking please? P2
    "Regenerative braking systems" are most commonly used in modern hybrid electric cars are thr system is a lot safer than a normal braking system!

    A regenerative braking system does two primary things:

    1. Converts Electrical energy into Chemical energy to power the battery in the car.

    2. When the regenerative brakes are applied by the driver, it puts the motor into a Reverse state. As a result, this slows down the wheels which allows the car to come to a stop!

    It's advantageous over a normal braking system as normal brakes convert the kinetic energy into sound and thermal energy. But in a regenerative braking system, the energy is converted into chemical energy so it's not wasted! But stored instead.

    Hope this helps!
    If you want a hand with any other topics in P2 then let me know.
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    (Original post by t.thompson22)
    If you want a hand with any other topics in P2 then let me know.
    Heya could you possibly explain how fuses/circuit breakers work?

    I understand that fuses melt when the live wire touches a casing and that it's something to do with sending a high current through earth wire?? Not sure though...

    And is a circuit breaker something to do with a change between the live and neutral wire?

    Thanks
 
 
 

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