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3-4.
the instantaneous power
p
(
t
) absorbed by the element shown is plotted below. assume that
there is no initial stored energy.
3
.
besides
t
= 0, at which time(s) is/are the net energy absorbed by the element equal to zero?

Apump is used to circulate hot water in a home heating system. water enters the well-insulated pump operating at steady state at a rate of 0.42 gal/min. the inlet pressure and temperature are 14.7 lbf/in.2, and 180°f, respectively; at the exit the pressure is 60 lbf/in.2 the pump requires 1/15 hp of power input. water can be modeled as an incompressible substance with constant density of 60.58 lb/ft3 and constant specific heat of 1 btu/lb or. neglecting kinetic and potential energy effects, determine the temperature change, in °r, as the water flows through the pump.