張力

（重定向自张力

處於平衡狀態的系統

${\displaystyle \sum _{}{\vec {F}}=0}$ [1]

${\displaystyle \sum _{}{\vec {F}}={\vec {T}}+m{\vec {g}}=0}$ [1]

處於有淨力狀態的系統

${\displaystyle \sum _{}{\vec {F}}\neq 0}$[1]

${\displaystyle \sum {\vec {F}}=T-mg\neq 0}$[1]

参考资料

1. Physics for Scientists and Engineers with Modern Physics, Section 5.7. Seventh Edition, Brooks/Cole Cengage Learning, 2008.