For example, if t* is the time you hit the ground, then t* satisfies the equation h - 1/2 g ^2 = 0.

例如,如果在 t* 时刻落地,那 t* 就满足等式 h - 1/2 g ? ^2 = 0

耶鲁公开课 - 基础物理课程节选

Let us say P for plane, G for ground, O for object.

我们定义 P 是平面,G 是地面,O 是物体

耶鲁公开课 - 基础物理课程节选

Remember, you've got to keep track of the sign of acceleration, so if you're picking up speed towards the ground, a is negative, so it will be g plus a, but a is a negative number.

记住,一定要注意加速度的符号,所以当你加速下降的时候,a 是负的,还是 g 加上 a,但是 a 是负数

耶鲁公开课 - 基础物理课程节选