[填空题]
(a) If a volcano spewkmdbd s9: 46huq8ly, b*sg iajgbrh52x, 9n0 ys a 500-kg rock vertically upward a distance of 500 m, what was its velocity when it ,s g8y rybnj92*q5x b liagh,0left the volcano? $\approx$ m/s
(b) If the volcano spews the equivalent of 1000 rocks of this size every minute, what is its power output? $\approx$ $a\times10^b$ W a = b =
