My group is to teach a lesson to our AP Physics class on a lesson from our book. We got lesson 92, which deals with Viscous Fluids, Surface Tension, and Elastic Properties of Solids. Since theres 3 people, we each got one and lucky me got surface tension. I have to be able to discuss this pretty darn throughly, explaining anything about it. I see that theres an equation, gamma = F/L Answer being in N/m 's I have some info from my book but there is these force diagrams that i have NO clue how im going to explain, and maybe thats why i think i dont understand this. It gives an example of a needle on top of water. Needle weights .008 N so whats the max. ^ force of the water....it would be .001. This force diagram shows a Tx on both sides of the needle 2 Ty's up and to T's going at feta angle. I dont get that. I understand everything else. Where are all these forces coming from? Ok, maybe im making this too complicated...or undercomplicating it. Im not sure. Can someone give me a general info on surface tension so that they can solve problems dealing with them and i not sound like a total moron when up in front of the class? Thanks in advanced, sry for such a long post..