1. The problem statement, all variables and given/known data If vitreous bottle is full of water and we strike with a palm from the top to the bottleneck, we can knock out the bottom of the bottle. Why? How to evaluate the force which knocks out the bottom of the bottle? 3. The attempt at a solution Because water has constant pressure: Pressure on the top = Force applied / neck area=Pressure on the bottom = Force bottom/ bottom areaForce bottom = Force top * bottom area / neck area So we knock out the bottom of the bottle because the force gets magnified. Now I need to evaluate "Force top". Let's say that the mass of the palm is M, and it moves with speed v before strike. The strike takes time moment which is equal to t. So then this means that: Force top = M*v/t And we get that: Force bottom = M*v/t * bottom area / neck area So is the "Force bottom" evaluated correctly in this problem? Don't I miss anything? Thanks in advance.