When you say the rope is under tension being pulled from both sides by a certain force, the tension is not 0 just because this T and that T cancel.

当绳子被绷紧,即两端被拉伸时,拉力并不为 0,因为这个 T 和那个 T 相互抵消了

耶鲁公开课 - 基础物理课程节选

Suppose you are being pulled by my favorite animals -- the elephants -- from both sides by equal force.

假设我最喜欢的动物,大象从两边拉你

耶鲁公开课 - 基础物理课程节选