We are constantly looking for values of F and we're constantly looking for responses or bodies to a known force.

我们不断地寻找 F 的值,我们不断地探索已知力对物体的作用

耶鲁公开课 - 基础物理课程节选

It will typically look like this and the formula we say is F = - kx, where k is called "The force constant."

图像看上去一般就像这样,对应的式子是 F = - kx,k 叫做"弹性系数"

耶鲁公开课 - 基础物理课程节选

F = ma is universally true, independent of the nature of the force acting on a body.

= ma 是一条普适定律,与作用在物体上的力的属性无关

耶鲁公开课 - 基础物理课程节选

The only force acting on this guy is this little f.

这个物体只受一个力的作用,也就是 f

耶鲁公开课 - 基础物理课程节选

We did the comparison with the elephant or something; a is the second derivative of x and for this problem, when F is due to a spring, we know the force is that by studying the spring.

我们也已经把它与大象或其它东西作过比较,a 是 x 的二阶导数,在这个问题中,F 是由弹簧产生的,我们在讨论弹簧问题时已经知道了力的大小

耶鲁公开课 - 基础物理课程节选