 So here's a related problem, another pendulum one. It's not the worksheet that you have to turn into me but it will help your understanding of how to solve some of these pendulum problems. How long does a simple pendulum on earth have to be so that it has a one oscillation per second? So by long I'm talking about the length of the pendulum. To remind you, I've got an equation which relates the length of the pendulum to the angular frequency. I also have an equation that relates the period of the pendulum to the angular frequency. We could do some algebra here to plug in and solve for the period in terms of the length, which is an equation you'll often see about pendulums. But we're going to break this down step by step. So if I start with my equation here which relates the period to the angular frequency. Well if I've got one oscillation per second that means each oscillation takes one second. So when I plug in that 2 pi over one second, I come up with an angular frequency of 6.2832 radians per second. Now I have kept a little bit more significant digits here for a reason and that's because of something I'm going to do later on in this problem. So now I go to my second equation which relates the angular frequency to the length of the pendulum. But since I want to solve for length, I'm definitely going to have to do some algebra. So the first thing I'm going to do is I'm going to square both sides of the equation. And that's going to lead me to an equation which says omega squared equals G over L. So I've gotten rid of the square root part. Now I can do a little bit more algebra to actually solve for the length of the pendulum in terms of gravity and that omega squared value. When I plug my values in now, I can go ahead and get my answer that this pendulum has to be 0.24824 meters. And again I've got more significant digits than I need, but we'll use that here in this next part.