I'm gonna exert a force on the wall, and the wall has to exert a force back.

我要对墙壁施加一个力，墙壁必须向后施加一个力。

Or you could say it's going to exert a force on that asteroid.

或者你可以说它将对该小行星施加一个力。

Non-contact forces don't have to touch an object to exert a force on it.

非接触力不必接触物体即可对其施加力。

If another astronaut pushed on you, they'd have to exert a force, but if you stood on a scale in space it wouldn't register anything.

如果另一个宇航员想推动你，他们必须施加一个力，但如果你站在太空中的体重秤上，它就不会有任何显示。