[理工] [動力]-成大95-機械-考題
http://0rz.tw/JtJQO
95年成大機械第四題
為什麼我用
ΣMA=(ΣMA)eff 算的話 和答案不一樣
一定要用ΣMG=(ΣMG)eff算嗎???
參考書的答案
ΣMG=IGα
0.5mg*2=(1/12)m*4*4*α
α=3g/4
可是我ㄧ開始用ΣMA=(ΣMA)eff
mg*2=(1/12)m*4*4*α+m*2*α*2
α=3g/8
到底是哪裡算錯了?
請各位幫忙指正一下
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