PHYSICS4A_2025_ZiTongCheng

 ZiTong Cheng For this experiment, we first shot the video of the car's movement, then obtained the speed of the car through the video analysis software, then established the motion model and calculated the equation through desmos to obtain our estimate, and then wrote all the data in the table for comparison. The data we get: and the distance the hanging mass moved before it hits the ground is d = 0.275 +/- 0.01 m. Questions： 1. Comparison Between Predicted and Measured Velocity: When the hanging mass varied, the measured velocity was relatively close to the predicted velocity, but there was a 6-10% difference in most cases. The discrepancy became more noticeable as the hanging mass increased. Similarly, when the mass of the car changed, the measured values deviated from the predictions by around 15% in some cases. While most of the measurements were reasonably close to the initial predictions, the differences could be attributed to factors such as friction, irregularities on the...

 data：                                                                                   data 1                                                                                data 2 graph： data 1 data 2 Questions: 1. How should we adjust the masses of objects A and C? We'll conduct experiments starting with 250g for the first test and then jump to 2kg for the second test. This extreme contrast helps reveal how the system behaves under vastly different loads. The significant mass difference will clearly show how weight changes affect the system's performance. 2. Are the pulleys tr...

 What I do in this project                                                              ZiTongCheng 1. I finished everything in the powerpoint except for page five. （Except for video analysis data and uncertainty, all other things in ppt are almost made by me.） 2. I finished all the code parts, including debugging the code, increasing the number of rockets, drawing, and so on. 3. I've always had the rocket, which is a difficult task for a scatterbrain like me.

 ppt link： https://docs.google.com/presentation/d/1ynQ0dC7zx61mJdpkjAijQ555PO4LrtOV62RWYV7QkMA/edit?usp=sharing

 Acceleration from Motion Detector 1. I measure the volocity of the ball, and also the displacement of the ball more in that period by motion detector. 2.We set up the lab equipments and connected to the computer, open the Logger Pro, and start our lab. Place the Motion detector 1.5 meters away and hold the ball 20cm away from the motion detector. hold it still. When we start recording data, we release the ball, after it hits the ground, we stop collecting data, and analyze the data by Logger Pro. Measuring the velocity of the ball by motion detector, and divided the speed into veritcal speed and horizontal speed. Using Logger Pro to analyze the graphs, clik the analysis bottom and choose linear fit and quadratic fit to spearately analyze the graph to get the equations. Then we can get the frist acceleration from the equation of horizontal speed vs time graph, and get the another acceleration from the equation of vertical postion vs time graph by take derivative of the equatio...