• Experiment 4 - The Competition Between Brownian Motion and Directed Forces
• 1. The goal of this experiment is to observe random and directed motion at the same time.Imagine starting with the setup from lab 3 (where we saw purely random motion).What would you have to change in the setup to introduce directed motion?
• 2. What forces dominate when mostly random motion is observed?
• 3. What forces dominate when mostly vertical-directed motion is observed?
• If you graph the log-log plot of a power law function y=axⁿ, what would you expect the slope of the log-log graph to be proportional to? What shape should the log-log plot be? (linear, exponential, etc.)
• Suppose you start with the equationy=ax² where a is a constant. If you take the log of both sides of the equation, what does your new equation become? (Expand this equation so that it is the sum of logs)
• Starting with your answer to the previous question, what is the value of your slope if you were to graph this new equation?
• In lab 4, if the slope of your log(R²) vs. log(t) graph is equal to 2, you have purely directed motion. What does this suggest about the shape of your R²vs. t graph in this case? (Is it linear, exponential, etc.)
• In lab 4, if the slope of your log(R²) vs. log(t) graph is equal to 1, you have purely random motion. What does this suggest about the shape of your R²vs. t graph in this case? (Is it linear, exponential, etc.)