One night, a toddler is dropping eggs from a windowof a building which is 20 feet above ground. A neighbor, hearing the commotion, looks through her window which is 15 feet from the toddler's window, on the same wall of the building, and at the same height. She shines a flashlight from her window on one of the falling eggs. How fast is the shadow of this egg moving on the ground when the egg is halfway to the ground? The prof did this in class and got an answer of 42 m/sec. The answer in the back of the book says 76 ft/sec. I get the same answer as the prof, but I'm not sure if it's correct. Is the book wrong??