= Consider a 3-Curie Ir 192 point source (energy = 300keV). Radiation Health Physicists are contemplating using either lead (density = 11.35 g/cc) or concrete (2.2 g/cc) as shielding to be placed 3 m away from this point source. 1. What is the radiation exposure rate 1m from this source? R/hr at 1 meter/Curie of the point I-192 source = 2. What is the radiation exposure rate (in R/hr) 3 m from this source? 3. What is the mass attenuation coefficient (cm^2/g) of lead at this energy? 4. What is the linear attenuation coefficient (cm^-1) of lead at this energy?