 In this lab, you're going to be looking at the energies involved in a pendulum that is swinging back and forth. First, we're going to measure the mass of the bob. For this lab, please take a bob that is around 50 grams. Then, you're also going to measure the diameter of the bob. Now you're going to set up the photogate as low as possible, and you're going to put some protective blocks in front of it, so that when we're swinging the pendulum, that there is no risk of actually hitting the photogate itself. It's quite expensive equipment, and we don't want to destroy it. When you turn on the photogate and put it on gate position, you will see that the timer will count for as long as the pendulum is obstructing the photogate. We will use this to calculate the speed of the pendulum at the lowest point by using some kinematics. We already measured the diameter, we know the time, or we can measure the time that it will take to pass, so we can calculate the speed. After each time, just put the reset button to be able to measure again. Now before we can start the experiment, we have to measure the lowest height of the pendulum. Try to measure the height of the center of mass. So if your pendulum doesn't have a marking yet, maybe you want to put a marker somewhere where you think the center of mass is. So here I would measure my lowest height at around 11.1 cm. And then you're going to put the photogate back into the lowest position of the pendulum. Now you're going to put your pendulum to a certain initial height, and you release it from there. You repeat this about three times so that we get three different time measurements for the same height. Now it's time to do the analysis. So you start by putting your data in your excel sheet, put the mass of the bob, its diameter, then for each run you put the height from where you released it, the lowest height of the bob, which is actually going to be, if you don't change your pendulum, set up the same for all the runs. And then the three times you measured. Over here you're calculating the average of those three times. Please use Excel formulas, don't calculate it outside of Excel. Then here you're calculating the velocity, or actually better the speed, based on the average time and the diameter of the bob. Based on that speed you're going to calculate the kinetic energy at the bottom. The potential energy of the bottom you're calculating it based on the lowest height and the mass of the bob. Then you add those two up to get the total mechanical energy at the bottom and the potential energy at the top. You're calculating this one based on your height at the highest point and the mass of the bob. Once you're done with that you're repeating the whole thing for six different heights. So use different heights and redo the whole calculation and hopefully you will see a pattern if you're comparing the potential energy at the top, which as there is no kinetic energy is the mechanical energy at the top and the total mechanical energy at the bottom. The question that I wanted to answer in the end in this lab is is the energy conserved in the system, in each of those rods? So you answer one for yes, zero for no, and of course there are uncertainties here which we didn't look at so consider if they are within the significant figures. See I used some useful amount of significant figures to see if within significant figures it's conserved. So when you calculate your energies please consider the significant figures here. We're not going to do a full error analysis which is going to base it on the number of sig figs. And then that's it for the first part of the lab.