Once a kid smaller than you punches you, if you have greater inertia than the smaller kid, then smaller kid will be the one who will get hurt.
If you are very angry and you suddenly punch a hard wall, the wall will not collapse for it has greater inertia, instead, you will feel the pain and soon, you will scream!
You can control your speed by applying lesser force in you feet when you run fast so that you will not get into an accident. (The speed of an object is directly proportional to the force applied on it.)
You have to exert greater effort and get tired easily if there is a race for running. You have to exert more effort so that you will be faster.
There is the concept of playing the see-saw! We can play see-saw I really love that game!
We always feel pain when punching an object especially if it is hard because the force we applied on that object will go back to you! Ouch! That will really hurt!