Since the beginning of this year, Hubei has suffered a drought once in 50 years. In order to fight drought and ensure a bumper harvest, farmers have dug wells to save themselves. A pump can pump 600 k

Since the beginning of this year, Hubei has suffered a drought once in 50 years. In order to fight drought and ensure a bumper harvest, farmers have dug wells to save themselves. A pump can pump 600 kilograms per minute. (1) 12m high water column pressure:

p =ρGH = 1× 103kg/m3× 10N/kg× 12m = 1.2× 105 pa；

(2)G = mg = 600kg× 10N/kg = 6000n，

The pump can do useful work every minute;

W useful = GH = 6000 n×12m = 7.2×104j;

(3)√η= W is always useful,

∴ Total work that the pump can do per minute:

W Total =W Useful η = 7.2×104J60% =1.2×105j,

Total power of the pump:

P=W total t =1.2×105j60s = 2000w = 2kw.

Answer: (1) 12m high water column produces a pressure of 1.2× 105 Pa;

(2) The useful work that the pump can do per minute is 7.2×104j; ;

(3) The total power of the pump is 2kW. ..