A 65−kg person is accidentally exposed for 240 s to a 15−mCi source of beta radiation coming from a sample of 90Sr. (a) What is the activity of the radiation source in disintegrations per second? In becquerels?
(b) Each beta particle has an energy of $8.75 \times 10⁻¹⁴ and 7.5 of the radiation is absorbed by the person. Assuming that the absorbed radiation is spread over the person'sentire body, calculate the absorbed dose in rads and in grays.
(c) If theRBE of the beta particles is 1.0, what is the effective dose inmrem and in sieverts?
(d) How does the magnitude of this dose of radiationcompare with that of a mammogram ( 300mrem )?
