This lab was the first virtual lab that I ever wrote. Well, I should say that this was the first virtual lab that I ever adapted. A colleague of mine wrote the “first edition” of this lab for a college physics course and I rewrote it for use in my high school physics class because I was so impressed with the results. Not only are the results astoundingly good, but the graphs that students prepare are very impressive and really help them to “see” the energy exchange in a collision. I have to say…this is my personal favorite virtual lab! Keep in mind when you do this lab with your students that not every lab group will get the same results. The applet does have some variation, so although it may be helpful for them to look at another group’s results to “guide” them on their own analysis, their answers may be very different when calculated.