A box of mass 44 kg is pushed hard enough to set it in motion across a flat surface. The coefficient of kinetic friction between the box and the surface µk = 0.48. What minimum pushing force is needed to keep the box moving at a constant velocity? a 231n
b 207n
c 178n
d 283n

6–48 bananas are to be cooled from 24 to 138c at a rate of 215 kg/h by a refrigeration system. the power input to the refrigerator is 1.4 kw. determine the rate of cooling, in kj/ min, and the cop of the refrigerator. the specific heat of banana above freezing is 3.35 kj/kg·8c.