起重机以0.1m/s的速度将重400N的重物匀速提高5m,起重机做功20002000J,它的功率是0.040.04KW.

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  • (1)起重机做功:W=Gh=400N×5m=2000J;(2)∵v= s t ,∴t= s v = 5m 0.1m/s =50s起重机做功的功率:P= W t = 2000J 50s =40W=0.04kW;故答案为:20...