An alert physics student stands beside the tracks as a train rolls slowly past. He notes that the frequency of the train whistle is 465 Hz when the train is approaching him and 441 Hz when the train is receding from him. Using these frequencies, he calculates the speed of the train. What value does he find?
Lecture 25 1 Recall: Focal lengths converging lens f diverging lens f 2 Recall: Images with Convex Lenses (2) § We start with a ray along the optical axis of the lens that passes straight through the lens that defines the bottom of the image. § A second ray is then drawn from the top of the object parallel to the optical axis • This ray is focused through the focal point on the oth