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Quick rate of decay qs

Last part what equation we using?

Power = work done/time?

And what are we trying to find.
Reply 1
Also the question after asks me to work out the mass.

Why is the mr 0.239?
well if each decay gives 8.2x10-13 Joules, yes you would need to use P=e/t, and dN/dt = A = LambdaN.
(
)The rate of decay x the energy per decay would give you the power. So set up the equation A x 8,2x10-13=2.5,

Mr is always stated a grams per mol, so 0.239 is the mr of Plutonium in kg
(edited 6 years ago)
Bq is number of decays per second
W is Joules per second

each decay releases 8.2E-13 J of energy
how many decays per second are needed to release 2.5J per second?
Reply 4
Original post by Formless
well if each decay gives 8.2x10-13 Joules, yes you would need to use P=e/t, and dN/dt = A = LambdaN.
(
)The rate of decay x the energy per decay would give you the power. So set up the equation A x 8,2x10-13=2.5,

Mr is always stated a grams per mol, so 0.239 is the mr of Plutonium in kg


Cheers
AQA?
Reply 6
20170619_192833.jpg
Original post by Joinedup
Bq is number of decays per second
W is Joules per second

each decay releases 8.2E-13 J of energy
how many decays per second are needed to release 2.5J per second?

Would this be alright?
Reply 7
Original post by Formless
AQA?


OCR, ****ing hate physics man.
Original post by Super199
20170619_192833.jpg
Would this be alright?


it's a 'show that' question... probably a one marker
I'd probably have said

Power = energy per decay * number of decays per second
2.5 = (8.2Ɨ10-13) * (3.0Ɨ1012) (to 2 s.f.)

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