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

Ahouse has the following electrical appliance usage (1) single 40w lamp used for 4 hours per day (2) single 60w fan used for 12 hours per day (3) single 200w refrigerator that runs 24 hours per day with compressor run 12 hours and off 12 hours find the solar power inverter size in watt with correction factor of 1.25.

Abrake has a normal braking torque of 2.8 kip in and heat-dissipating cast-iron surfaces whose mass is 40 lbm. suppose a load is brought to rest in 8.0 s from an initial angular speed of 1600 rev/min using the normal braking torque; estimate the temperature rise of the heat dissipating surfaces.

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false