In this activity, you will use a model to identify how electric current depends on applied voltage.

This model shows a microscopic look at how electric current flows through a wire connected to a battery. It shows how electric current depends on the number of free electrons and how fast these red electrons are traveling towards the positive end of a battery. This speed depends on (1) the applied voltage difference and (2) the obstacles that the electrons encounter in their way, which are represented in this model by blue atoms.

In this model, time is represented in terms of ticks, which can be adjusted using the slider at the top to slow down or speed up the model. 

To use the model:

1) Click SETUP then GO. You will start to see electrons flow through the wire, see data readings on the monitors, and a plot form on the graph. 

2) You can change the voltage at any time, even while the model is running. However, to have accurate comparable readings it might be best to hit SET-UP and GO to reset the model after you've changed the parameters to where you'd like them.