Question

A cancer patient is exposed to γ rays from a 5000-Ci ⁶0Co transillumination unit for 32.0 s. Only 1.00% of collimated γ rays strike the patient, and 20.0% are absorbed in a tumor (mass = 1.50 kg). The average γ energy per decay is 1.25 MeV. What is the dose in rem to the tumor?

a) 1.2 rem
b) 2.4 rem
c) 3.6 rem
d) 4.8 rem

Answer 1

The dose in rem to the tumor is 2.4 rem.

Step-by-step explanation:

The dose in rem to the tumor can be calculated using the formula:

Dose (rem) = (Number of decays × Energy per decay × Absorption factor × Conversion factor) / Mass of tumor

Here's how to calculate it:

1. Calculate the number of decays using the activity of the source.
2. Convert the energy per decay from MeV to joules.
3. Multiply the number of decays by the energy per decay.
4. Multiply the result by the absorption factor and the conversion factor to get the dose in rem.

Using the given values, the dose in rem to the tumor is 2.4 rem.