Dale Yoder-Short

These are an extensive set of interactive physics illustrations for use on a computer. They require Geometer's Sketchpad from Key Curriculum Press. In these illustrations, the user can interactively change parameters and see the results. Sketches involving motion are also animated. The sketches show calculated results as well as changing diagrams as parameters change. I have attempted to incorporate common sense limitations into the illustrations, e.g., the index of refraction of light is not

This interactive sketch produces the image formed by a converging lens as the user moves the object. It requires Geometer's Sketchpad to run. The sketch shows classic ray diagrams and calculations for an image formed by an object placed anywhere in front of or behind a converging lens. It also illustrates a three dimensional figure and focusing an image on a screen. It can be used as a dynamic teacher illustration or as an interactive student exploration. You must have Geometer's Sketchpad to ru

This interactive sketch shows several models of the solar system. It requires Geometer's Sketchpad to run. The sketch shows the Ptolemaic model with rotating spheres and epicycles. It also shows the heliocentric model and retrograde motion. Finally it shows Kepler's third law for planets, moons and satellites. The user can control orbital radius and central mass. It can be used as a dynamic teacher illustration or an interactive student exploration. It was created using Geometer's Sketchpad and

This interactive sketch creates the position, and velocity graphs of one or two objects simultaneously in motion along a straight line as they are moving. This sketch requires Geometer's Sketchpad to open and run. The user can control the initial position, velocity and acceleration of each of the two objects. The sketch shows the motion of the objects on a straight line and the graph of their position vs time or velocity vs time.

This interactive sketch allows the user to mix primary colors in any proportion and see the result. The user can vary the amount of red, green and blue as on a computer screen; or the user can vary the amount of cyan, magenta and yellow as in a printer. This can be used as a dynamic teacher demonstration or as an interactive student exploration. This application was created using Geometer's Sketchpad and requires Geometer's Sketchpad to run it. Dale Yoder-Short

This interactive sketch produces the trajectory of a projectile. It requires Geometer's Sketchpad to run. The user can specify the launch angle and velocity and launch the projectile. You can also include air drag for the projectile. The sketch shows the projectile moving on its path and calculates the components of the position and velocity as it moves along its path. This can be used as a dynamic teacher illustration or as an interactive student exploration. You must have Geometer's Sketchpad

This kinematic motion situation in mechanics is a dynamic sketch of an object falling in a moving elevator. This sketch requires Geometer's Sketchpad to run it. The sketch shows the object falling from the ceiling of the elevator as the elevator rises or falls. It calculates the position and speed of the elevator and of the object as time passes. The user can control the height, initial speed and acceleration of the elevator. You must have Geometer's Sketchpad to use this sketch.

This sketch illustrates an object hanging form two wires. It requires Geometer's Sketchpad to run. The user can control the size of the hanging weight and the angle each wire makes with the horizontal. The sketch shows and calculates the force needed in each wire. It can be used as a dynamic illustration or as a student activity. This sketch was created with Geometer's Sketchpad and needs it to run.

This illustration obtains the work done by a force in several situations. It requires Geometer's Sketchpad to run. The sketch shows the force and calculates the work done by that force. It can be used as a dynamic illustration or as a student activity. It was created using Geometer's Sketchpad and needs it to run.