CH --00 Subskills: 1 Physics is all about making models, and we often model complex things with simple approximations that give a good description of the real phenomenon. We will examine how to think of a massive cable as a series of discrete masses. (a) We start with a chain of four blocks hanging from the ceiling. Each block has a weight W. The strings between the ceiling and the first block and between the other blocks are so light compared to the weight of the blocks that we can ignore the strings' masses. In other words, we can treat the strings as massless. Draw a force diagram for the second block from the top. (b) What is the tension in each of the 5 strings? (c) Now imagine we have a very long chain of N blocks and N+1 strings, where N is a very large number like one million so that each block and string is microscopic. The whole chain is 1 m long, so you can't even see the strings. It looks like a solid, flexible cable of metal. Write a function T(y) for the tension in a chain of length L and total weight W. Define any variables or coordinates you need, and state any approximations you may need.