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johnq2k7

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**energy flux density and and energy fluence question! work shown please help!**

A point source of Co-60 gamma rays emits equal numbers of photons of 1.17 and 1.33 MeV, giving a flux density of 5.7 x 10^9 photons/cm^2-sec at a specified location.

a.)What is the energy flux density there, expressed in J/m^2-min?

b.)What is the energy fluence of 1.17 MeV photons during 24 hours in J/m^2?

My work:

a.) 5.7 x 10^9 photons/cm^2-sec * (100 cm)^2/(1m^2)= 5.7 x 10^13 photons/m^2-sec

5.7 x 10^13 photons/m^2-sec * (60 sec/1min)= 3.42 x 10^15 photons/m^2-min

how do you convert photons/m^2-min to J/m^2-min for Co-60

do you find the rest energy of the molar mass which is 60 g/mol and multiply it by c^2

the correct answer is 685 J/m^2-min, how do you go from photons/m^2-min to J/m^2- min to find the energy flux density?

b.) 5.7 x 10^13 photons/m^2-sec * (86400 sec/24hr)= 5.7x10^13 photons/m^2

how do you convert photons/m^2 to J/m^2

the correct answer is suppose to be 4.62 x 10^5 J/m^2

how do you convert the photon units to joules

do you include the molar mass of Co-60 isotope some how

please help!