“Playing with Physics” apps allow interactive simulation of select physics phenomena.

The “Optical Instruments” is designed to show the course of rays when they are reflected on a mirror or refracted by a lens. The user can choose between a hollow and a convex mirror, or a converging and diverging lens. Use the mouse cursor to change the object distance and the size of the object, and the application will plot the course of the rays and list the properties of the image.