Light Intensity - IB Physics

I explain how to calculate light intensity and how to use proportional reasoning to find changes in light intensity based on the distance from a light source and on the amplitude of the light wave. Check out my channel for lecture videos on the entire IB physics curriculum organized by topic. A like & subscribe is always appreciated! 0:00 Variable, Unit, and Equation 1:21 Connection Between Spheres and Intensity 2:47 Example Problem 1 4:26 Example Problem 2 5:30 Proportional Reasoning 6:00 Example Proportional Reasoning Problem 1 6:52 Example Proportional Reasoning Problem 2