[填空题]
A window washer pulls herself upward using the buc(ml +c em/rte1ket-pulley apparatus shownt,0 .jax imw+yqk97j8cr 5zu7x q:a hb in Fig. 4-48. (a) How hard must she pull downward to raise hers yq+rwc 9 :xab08tq7j,k7h.i5uzamj x elf slowly at constant speed?
(b) If she increases this force by 15 % , what will her acceleration be? The mass of the person plus the bucket is 65 kg .
