A 1-mCi point source of 137Cs is located at the center of a sphere of concrete. The sphere has a diameter of 10 cm. The source emits photons of energy 0.662 MeV with a frequency of 0.845 per decay. (a) What is the total interaction coefficient of the concrete at the source photon energy

Acompressor compresses a gas, a pump compresses a liquid. for a given pressure ratio, why does it take more work to compress a gas in a compressor than a liquid in a pump? a)- for a given pressure ratio the average specific volume for a gas is much higher than the average specific volume for a liquid. b)- there is no difference. the only difference is the amount of heat generated (not work) c)- for a given pressure ratio the average volurge for a gas is much higher than the average volume for a liquid. d)-there is no difference