Have created a simulation for teaching of speed in Primary School.
Based this simulation by getting ideas from :
(1) The simulation by Prof Huang and Lookang
Features in this simulation:
(1) In "slow-down" mode when the objects are about to collide or reach either Towns.
(This is to ensure that the time for the actual collision or to reach town is as accurate as possible)
(2) Allows user to input the starting position and starting time.
(3) Shows the various distance (like distance from Town A, distance moved) to highlight the concepts of speed.
Teaching ideas with this simulation :
(1) Teacher to use this to demonstrate the concept of speed by showing them visually. Let them see how the formula (distance = speed * time) works and what happens during collision.
(2) Students to "play" with the applet to get conceptual understanding of speed.