[填空题]
Water flows over a dam at the rate of*w0jobym-c. m 650kg/s and falls vertically 81z;f)lmkmg4rf/nz2u+ t *(e *hi5zasw m before strikig+tks)*;zl e f(nh5/zfa42zmurw* ming the turbine blades. Calculate
(a) the speed of the water just before striking the turbine blades (neglect air resistance), $\approx$ m/s
(b) the rate at which mechanical energy is transferred to the turbine blades, assuming 58% efficiency. W