Static Equilibrium
2011-03-31 6:19 pm
圖片參考：http://imgcld.yimg.com/8/n/HA00270495/o/701103310027913873404191.jpg
1.I don't understand why the suggested solution explain F is minimum in the direction which is shown in the bottom fig.
2.How about the direction parallel to the horizontal
3.How should I find the direction of 'minimum force' in this kind of question
THX!
回答 (2)
2011-03-31 8:44 pm
✔ 最佳答案
This is just simple application of the principle of “triangle of forces”. The tension in the string T and the weight of the bob mg produce a resultant force R such that R = mg.sin(theta). This force R is in a direction perpendicular to the tension T and is pointing towards the vertical that shown on the diagram. Hence, the minimum force F needed in order to balance R is just a force equal in magnitude to R and acts in opposite direction to R. If the force F acts in other directions, it is apparent that it either increases or decreases the tension in the string.
2011-03-31 6:54 pm
收錄日期: 2021-04-29 17:39:45
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110331000051KK00279