I just made a significant update for this video on measuring work efficiency. To keep it low budget, I just included the option of using a power drill for measurement of work involving rotary motion. Since this option is barely described in the lab manual I decided to include it in the video. Most of you who teach environmental science may never use this activity because it seems more appropriate for physics or engineering. Nonetheless, I always use this activity when I teach environmental science because it is relatively easy to do and the calculations are reasonable. Furthermore, students should learn first-hand how energy conversion losses can be measured and minimized (in this case by choosing the ideal mass or rotation speed). Hopefully this update will make this activity more appealing because almost everyone has access to a power drill.