Find product kinetic energies in (α,γ) reaction

ElectricEel1
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Homework Statement



5.5 MeV alphas hit Be-9 and produce carbon with a gamma. the Q value is 10.65

I have to find the kinetic energy of the carbon nucleus and the gamma and I am to ignore the gamma ray momentum.

Homework Equations


T = p^2 / 2*m
Q = T_be + T_alpha - T_c - T_gam[/B]

The Attempt at a Solution



Momentum is conserved and I'm told to ignore the gammas momentum so I calculated the alpha momentum to be 202.56 MeV/c then used that as the carbon momentum and rearranged to find the kinetic energy as 1.7 MeV.

Then using the Q equation i rearranged to find T_gam but end up with -6.85 which doesn't work so I'm a little stuck now.

Thanks

edit: realized i had the equation the wrong way round and it should be Q = T_c + T_gam - T_alph

think it makes sense now
 
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ElectricEel1 said:
edit: realized i had the equation the wrong way round and it should be Q = T_c + T_gam - T_alph

think it makes sense now
That's how I interpreted the Q-value as well.
You can also check the masses of the nuclei to be sure, but the reaction certainly releases energy. C-12 is a very tightly bound nucleus.
 
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