Question

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普物-請問第41題

41。The surface of the continental United States has an area
of about 8x 106 km2 and an average elevation of about 500 m
(above sealevel. The average yearly rainfallis 75S cm.The frac-
tion ofthis rainwaterthatreturns tothe atmosphere by evapora-
tion is生the rest eventually flows into the ocean. Ifthe deerease
in gravitational potential energy of the water-Earth_ system
associated with that flow could be fully converted to eleetrieal
energy, what would be the average power? (The massoflm'of
water is 1000 kg.)

人
loon reaches its maximum height?
potential energy is taken to be Zere
its value atthe launch point) (D W

48 Avoleanicash ttowismovint
eneountersa8.0” upslope.The ff
up the slope before stopbing. As
the flow Ift the flow and thus
ground negligible: assume als
the front ot the flow is conserve