Answer:
1.32142x10^-3 Gy
Explanation:
Mass m = 63kg
Time t = 5.0s
Beta energy = 1.5x19^-13J
1 Ci = 3.7x10¹⁰
3.0Ci = 3x3.7x10¹⁰
= 11.1x10¹⁰decay/s
We have a total of 11.1x10¹⁰ beta particles produced per second
The question says there is 100% absorption
Et = (11.1x10¹⁰)x5x1.5x10^-13
= 0.08325
The radiation dose = Et/m
= 0.08325/63 kg
= 0.001321428J/kg
= 0.001321428 grays
Or 1.32142x10^-3 Gy
A perfect black body can’t be realized