二个英文物理题目[USA原版]

1 Romeo (73.0 kg) entertains Juliet (54.0 kg) by playing his guitar from the rear of their boat at rest in still water, 2.50 m away from Juliet who is in the front of the boat. After the serenade, Juliet carefully moves to the rear of the boat (away from shore) to plant a kiss on Romeo's cheek. How far does the 76.0 kg boat move toward the shore it is facing?

在静止的船尾若密欧(73.0kg)弹吉他取悦朱丽叶，朱丽叶离船头有2.5m远,小夜曲之后，朱丽叶小心地走到船尾（远离海岸），给若密欧一个吻，那么这只76.0kg的船将向海岸移动多远 ？
2 Batman, whose mass is 72.0 kg, is holding onto the free end of a 12.0 m rope, the other end of which is fixed to a tree limb above. He is able to get the rope in motion as only Batman knows how, eventually getting it to swing enough that he can reach a ledge when the rope makes a 58.0?angle with the vertical. How much work was done by the gravitational force on Batman in this maneuver?
一个美国留学生给的