The print version allows teachers to use the problem with their students without giving the students access to the archived answers.
Teachers can use the link to the archived problem to get ideas of student thinking.
Given the controlled situation graph, the students are asked to predict how the real-life situation will look in a graph. Often students don't understand the importance that the constant of time plays in a linear function. This exercise could also be used to compare controlled results vs. real-life results. Please email us.