A 2 lb weight stretches a spring 6 inches in equilibrium. An external force F .t / T sin 8t lb is applied to the weight, which is released from rest 2 inches below equilibrium. Find its displacement for t > 0.

6–43 a food department is kept at 2128c by a refrigerator in an environment at 308c. the total heat gain to the food department is estimated to be 3300 kj/h and the heat rejection in the condenser is 4800 kj/h. determine the power input to the compressor, in kw and the cop of the refrigerator.