A 30.0-kg child receives 2.65 × 10⁷ β particles, each with an energy of 4.60 × 10^-13 J. If the RBE = 0.78, how many millirem did the child receive?

Question

Quizplus · Accepted Answer

The dose in millirem is calculated using the formula: Dose (rem) = (Energy absorbed in J/kg) × RBE × 1000. First, calculate the total energy absorbed: 2.65 × 10^7 particles × 4.60 × 10^-13 J/particle = 1.219 × 10^-5 J. The energy absorbed per kg is 1.219 × 10^-5 J / 30 kg = 4.063 × 10^-7 J/kg. Then, Dose (rem) = 4.063 × 10^-7 J/kg × 0.78 = 3.17 × 10^-7 rem. Converting to millirem: 3.17 × 10^-7 rem × 1000 = 3.17 × 10^-4 millirem, which is approximately 3.2 × 10^-2 millirem.

A 300-Kg Child Receives 2