Tom d. spends his spare time running a bungee jumping service off the henley street bridge. he has a 153 ft long bungee cord (unstretched) that has a spring stiffness of 22 lb/ft. to test his bungee, he ties the bungee cord to the bridge railing, ties the other end to an unnamed person weighing 135 pounds, and then gently nudges the person off of the bridge. determine the professor's speed when the bungee cord starts to stretch.

Acommercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -35°c by rejecting waste heat to cooling water that enters the condenser at 18°c at a rate of 0.25 kg/s and leaves at 26°c. the refrigerant enters the condenser at 1.2 mpa and 50°c. if the compressor consumes 3.3 kw of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration load, (c) the cop, and (d) the minimum power input to the compressor for the same refrigeration load.