1. The problem statement, all variables and given/known data A pendulum is 0.8 m long and the bob has a mass of 1.0 kg. At the bottom of its swing, the bob's speed is 1.8 m/s. What is the tension in the string at the bottom of the swing? I don't even know how to get started on this problem, I think it has something to do with using the sin or cos but I can't find an example problem like this in my book.