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# Noob to forum, + unsolveable physics question Watch

1. Hi guys, new to the forum! Currently studying physics,biology, chemistry and business at as! I'm stuck on this physics question, any help would be greatly appreciated!

In a 1 kW laser, 2.3x1013 photons pass a fixed point each second. Calculate

a) The energy of each photon

4.35x10^-11 J

b) The frequency of each photon

6.56x10^22 Hz

A photon produced by this laser undergoes pair production, producing a muon / antimuon pair. Calculate:

c) The kinetic energy of each particle produced

I'm stuck on C, any help would be appreciated

So for photon energy I have 4.35x10^-11J

Rest energy for muon/antimuon pair= 2(105.659), convert into joules: 211.318 x (1.6x10^-19)= 3.381x10^-17

Then kinetic energy, (4.35x10^-11) - (3.381x10^-17)= (4.349x10^-11) / 2 divide by 2 for each particle=2.175x10^-11

2. Rest energy of muon is 105MeV=105x106​eV
3. Thanks, sorry I didn't put the units. I got the rest energy to be 105.659Mev which in joules for 2 muons is 3.381x10^-17 J (If my calculations are correct)
4. [
I'm stuck on C, any help would be appreciated

So for photon energy I have 4.35x10^-11J

Rest energy for muon/antimuon pair= 2(105.659), convert into joules: 211.318 x (1.6x10^-19)= 3.381x10^-17

Then kinetic energy, (4.35x10^-11) - (3.381x10^-17)= (4.349x10^-11) / 2 divide by 2 for each particle=2.175x10^-11

Don't forget that

Then continue.
Thanks, sorry I didn't put the units. I got the rest energy to be 105.659Mev which in joules for 2 muons is 3.381x10^-17 J (If my calculations are correct)
No, I got 3.381x10-11​J.
6. Ahhh thank you! I was converting mev straight into joules. School boy error haha!

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