PHY QUESTION~~~~~hurry!!!!
2009-10-04 12:17 pm
Jeff of the Jungle swings on a 7.6 m vine that initially makes an angle of 47 degree with the vertical.If Jeff starts at rest and has a mass of 73 kg, what is the tension in the vine at the lowest point of the swing?
回答 (1)
2009-10-04 6:49 pm
✔ 最佳答案
By the law of conservation of energy,Loss of G.P.E. = Gain of K.E.
mgh(1 - cos@) = 1/2 mv2
v = sqrt[2gh(1 - cos@)]
v = sqrt[2(10)(7.6)(1 - cos47*)]
Speed at the lowest point, v = 6.95 ms-1
At the lowest point,
T - mg = mv2 / h
T = mg + mv2 / h
T = (73)(10) + (73)(6.95)2 / 7.6
Tension, T = 1.19 X 103 N
參考: Physics king
收錄日期: 2021-04-19 15:28:16
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20091004000051KK02194