[填空题]
A window washer pulls herself upward using the bucket-pw fm67lr;xbh0ulley apparatus shown in*9 i nwz-vyc(gpu3 0zp Fig. 4-9p3v*g zuncy(w i0zp-48. (a) How hard must she pull downward to raise herself 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 .
