Hi, This problem relates to my final's project. I'm trying to quantify an impact on a human hand from a robot. I've thought about it in Watts, Joules and Newton's. But I ran into a problem when I thought about it like this: If I have the mechanism (in the drawing)- its energy when falling equals to T=mgh from its center of mass. Which means that in an impact when the rod stops- my hand will absorb all the energy. BUT if I'll get hit from point A it will hurt much more than point B since its linear speed is greater. But the rod will stop either way! Meaning I will absorb all the amount of energy... Am I wrong? Is the amount of energy is different along the rod (I know it does not make any sense). I will appreciate any help!