Okay, so with that, if you write the right forces,

本着这个原则如果你受力分析画对了
you will be just fine.

那就功德圆满了
You will be able to solve all the problems we have in mechanics.

你就可以解决我们即将碰到的所有力学问题
I'm going to now start doing simple problems in mechanics.

现在我来讲解几个简单的力学题目
They will start out simple and,

我们从简单的开始
as usual, they will get progressively more difficult.

我们照旧循序渐进慢慢加大难度
Let's start with our first triumph will be motion in 1D.

我们先从一维问题开始
Here is some object, it's 5 kilograms

这有一个物体 5 千克
and I apply 10 Newtons.

我对它施加 10 牛的力
Someone says, "What's the acceleration?"

有人就问了 "加速度是多少"
Everyone knows it is 10 over 5 equals 2.

大家都知道是 10 除以 5 等于 2
Now we know

现在我们知道