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AQA PHYA5 Option D: turning points - Special relativity question HELP

From the June 2015 paper, could anyone explain to me how to do this question please?





turning point q.jpg
(edited 7 years ago)
Original post by Music With Rocks
From the June 2015 paper, could anyone explain to me how to do this question please?



which q mate
Original post by Formless
which q mate


Hmmm my embedded images don't seem to be working lately, can you see it now?

turning point q.jpg
Original post by Music With Rocks
Hmmm my embedded images don't seem to be working lately, can you see it now?

turning point q.jpg



So find the mass of the electron when its at 0.98c
= (9.11x10^-31) /sqrt( 1-0.98^2)
=4.6x10^-30

E = mc^2

so multiply the above mass by c^2

(9.11x10^-31) x (3x10^8)^2 / sqrt( 1-0.98^2)
=4.6x10^-30 x (3x10^8)^2
=4.12x10^-13 J
(edited 7 years ago)
Original post by Formless

So find the mass of the electron when its at 0.98c
= (9.11x10^-31) /sqrt( 1-0.98^2)
=4.6x10^-30

E = mc^2

so multiply the above mass by c^2

(9.11x10^-31) x (3x10^8)^2 / sqrt( 1-0.98^2)
=4.6x10^-30 x (3x10^8)^2
=4.12x10^-13 J


That is perfect, thank you very much for the explanation :smile: I understand it now
Original post by Music With Rocks
That is perfect, thank you very much for the explanation :smile: I understand it now


No worries feel free to hit me up with queries, i dont feel quite ready for tomorrow aha
Original post by Formless
No worries feel free to hit me up with queries, i dont feel quite ready for tomorrow aha


I will certainly take up that offer haha, me neither I have been doing well in past papers but don't feel quite like I am there yet
Original post by Music With Rocks
I will certainly take up that offer haha, me neither I have been doing well in past papers but don't feel quite like I am there yet


Im just too excited that it my last exam dont want it to make me perform badly
Original post by Formless
Im just too excited that it my last exam dont want it to make me perform badly


Same here, I feel like I am done already but this exam is just as important as the others

Plus I am still knackered from having an exam this morning
Original post by Music With Rocks
Same here, I feel like I am done already but this exam is just as important as the others

Plus I am still knackered from having an exam this morning



Heard S2 Was v difficult. FP3 was okay ive heard. Which one did you do?
Original post by Formless
Heard S2 Was v difficult. FP3 was okay ive heard. Which one did you do?


S2 thank god haha, had a hard enough time with FP2. S2 wasn't too bad but I messed up a fair bit as I only left myself the weekend to revise it, so lots of dumb errors.I am definitely needing a good PHYA5 performance.
Original post by Music With Rocks
S2 thank god haha, had a hard enough time with FP2. S2 wasn't too bad but I messed up a fair bit as I only left myself the weekend to revise it, so lots of dumb errors.I am definitely needing a good PHYA5 performance.


Ah okay, good luck for tomo mate
Original post by Formless
Ah okay, good luck for tomo mate


Good luck to you too!

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