Core Practical 9: Relationship between the force on an object and its change in momentum

This video covers Core Practical 9 for Edexcel International A Level Physics. The aim of the experiment is to investigate the relationship between the force acting on an object and its change in momentum. In this lesson I walk through the full setup, the theory, the variables, the measurements, the calculations, and the uncertainties exactly as required by the specification. We use a trolley, a hanging mass, a bench pulley, a string, a light gate, and a stopwatch to measure two key times: the time the force acts and the time the trolley takes to pass through the light gate. From these we calculate the velocity, the impulse, and the change in momentum. We then compare F multiplied by time₂ with M multiplied by v to verify the impulse momentum relationship. The graph required is m multiplied by time₂ on the y axis against v on the x axis. I explain how this gives a straight line and how its gradient relates to M divided by g. I also cover all sources of uncertainty including ruler measurements, stopwatch timing, light gate timing, and how to combine percentage uncertainties to find the uncertainty in your value of g. If you have questions about any part of the method or want a worked example using real data, feel free to comment below. No ads, no sponsorships, just free content. If you found this useful, a small contribution goes a long way. Buy Me a Coffee: https://buymeacoffee.com/cconsta1w PayPal: https://paypal.me/doctorNoo