external force

基本解释

Every developer becomes aware of the concept of technical debt, whereby you make compromises in your design for the sake of some external force, such as schedule pressure.
每位开发人员都开始注意到技术债务的概念，您可能由此而迫于外部压力（例如日程压力）在设计中有所折衷。
If you are completely present, the external forces are no longer a problem, because there is only you and that external force, in this moment, and not a million other things you need to worry about.
如果你是完全专注于眼前的事情，那么外部因素将不再是问题。因为在此刻，唯有你和那个外部因素，没有成千上万的其它事情需要你担忧的。
If the external force on the squash racquet were zero, then it would continue to go always with the same velocity, the center of mass.
若壁球板受外力为，它可能会一直运动,保持同样的速度，而整体的中心。

So the force that you're pushing down on here is the external pressure times the area.
或者压缩功的概念,在活塞上施加压力。
麻省理工公开课 - 热力学与动力学课程节选

While with effort the water can be pushed out of its puddles, when the external force is no longer applied, the water will re-puddle exactly as before.
WHITEHOUSE: Engage and Connect
It could be that being a risk-taker drives you to play more games, or that some external force makes you both play games AND be an unsafe driver.
FORBES: New Study Claims Gamers are More Unsafe Drivers
Had I been stopped by some external force?
ENGADGET: This is the Modem World: It's my movie

外力
The basic idea of the active contour is to make a contour move to the destination with the internal and external force.
活动轮廓的基本思想是利用一条曲线在内力和外力的共同作用下,移动到我们所期望的位置。
物理学
外力