>>148-150
できない。速度を取得して自分でf=maで計算する
http://answers.unity3d.com/questions/200633/what-force-did-collider-collide-with.html
http://forum.unity3d.com/threads/23746-getting-impact-FORCE-not-just-velocity
http://answers.unity3d.com/questions/201823/how-to-implement-if-hit-with-certain-force.html