I don't have to worry about any internal forces, now these tensions become internal forces.

我不用担心任何内力，现在这些紧张变成内力。

And so that's different from an intramolecular force, which is the force within a molecule.

所以这与分子内力不同，分子内力分子内的力。

But of course, it's not an actual intramolecular force.

但当然，它不真正的分子内力。

Underwater pees are also lengthier because the external water pressure counteracts the internal forces resulting from elevation difference.

水下小便也更长，因为外部水压抵拔差异产生的内力。

And the shape of the spring causes internal forces that try to return the spring to its original shape.

弹簧的形状会产生内力，试图将弹簧恢复到原来的形状。

Elastic objects are made of materials and designed, so they have internal or inside forces that try to return them to their original shape.

弹性体由材料制成并经过设计，因此它们具有试图使其恢复到原始形状的内力或内部力。