1. The problem statement, all variables and given/known data See attachment please. 2. Relevant equations The definition for Young's modulus. Newtons second law. Pythagoras' formula. 3. The attempt at a solution I know from physics 1 that I have to apply F=ma to the point where two "triangles" meet. The phrase "the tension" implies that the tension is the same everywhere on the string. If this is true, though, my answer for tension does not fit with the book's answer. I do not know how the tension would be related to the force when the force is perpendicular to object that is extended. Please provide me with hints, i am clueless. I attempted a solution assuming that extension of the string was solely vertical, but I got L_0/50 for y. The answer is L_0/20. The tension is supposedly 5mg. If I plug that into my equation for T, it spits out L_0/20=y. Otherwise, I have not a clue how to get L_0/20=y. Thanks!