(2009? Jiamusi) As shown in the figure, the construction workers use the pulley block to lift the mud bucket with a weight of 200N, and the tension used is 80 N. If the workers mix the mud bucket evenly within 5s, As can be seen from the figure, the pulley block is loaded by three ropes, so S = 3h = 3x2m = 6m.

The total work done by this worker is: w total =Fs=80N×6m=480J.

So the power of the pulling force is: P=W, and the total T = 480J5S = 96W.

Mechanical efficiency of pulley block η = ghfs = 200 n× 2m480j? =83.3%

So the answer is: 96; 83.3%.