Fish are considered a renewable resource. however, some scientists believe that earth's oceans are running out of economically valuable fish. what is the most likely reason for this?
a. they are no longer reproducing.
b. they are being harvested faster than they can replenish themselves.
c. they are all being eaten by other predators in the oceans, such as sharks and whales.
d. they are migrating to other bodies of water.

4r-134a enters the condenser of a residential heat pump at 800 kpa and 50°c at a rate of 0.022 kg/s and leaves at 750 kpa subcooled by 3°c. the refrigerant enters the compressor at 200 kpa superheated by 4°c determine (a) the isentropic efficiency of the compressor, (b) the rate of heat supplied to the heated room, and (c) the cop of the heat pump. also, determine (d) the cop and rate of heat supplied to the heated room if this heat pump operated on the ideal vapor-compression cycle between the pressure limits of 200 and 800 kpa. (0.757, 4.37 kw, 5.12, 6.18, 3.91 kw)