力 學 問 題
回答 (2)
2007-04-04 6:37 am
✔ 最佳答案
Total loss of potential energy = 60g x (10+3) J = 7800 JUsing work done = loss of potential energy
(F - 60g)x 3 = 7800
where F is the resistance of water, and (F-60g) is the net force acting on the man by the water.
i.e. F = (7800/3 + 60g) N = 3200 N
2007-04-05 4:41 am
mg(H+h)=(friction)X(H+h)
(60)(10)(10+3)=(friction)X(10+3)
friction=600N
(60)(10)(10+3)=(friction)X(10+3)
friction=600N
收錄日期: 2021-04-23 19:50:21
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070403000051KK04690