Question:
Physics---electrostatics
2008-01-09 12:20 am
回答 (1)
2008-01-09 2:03 am
✔ 最佳答案
Let T be the tension of each string, then:T cos θ = mg
T = mg/cos θ
T sin θ = Q2/4πε0r2
mg tan θ = Q2/4πε0r2
mg sin θ = Q2/4πε0r2 (tan θ ~ sin θ for small θ)
mg (r/2l) = Q2/4πε0r2
r3 = Q2l/πε0mg
r = 3√(Q2l/πε0mg)
參考: My physics knowledge
收錄日期: 2021-04-22 00:33:58
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080108000051KK01935