Every do often, we may be doing data analysis of events recorded by video. This might be a ball thrown through the air, a video game, a cool YouTube video you find, or anything that has motion involved. The goal is to get your data from the video. We will have three main ways of doing this.
One way is a scaling exercise. Quite literally, you can measure the sizes and distances on the computer monitor. If you know the actual size of on object in the video (perhaps a person or meterstick), you can scale lengths of any other object in the video to get its size, or to measure the distance the object moves. The other quantity we need is time. This will require either timing the event on the video, which could include just reading the time stamp of the video or timing with a stopwatch if the video is running in real time.
The other two methods are very similar, and use software. Logger Pro, which is the software we use to run our Vernier sensors, and Tracker, a free online program, can have any video on your hard drive imported for analysis. It is really cool stuff, and below is a video that explains how to use Tracker to get data from a video where a ball is tossed in the air. Watch and learn, and then you will have chances to do this with any video we use during the year (or better yet, on your own when you are curious about something you capture on video).
Keep in mind, you can upload video from a camcorder or your cell phone onto your computer. What about if you want to analyze an existing YouTube video, or if you want to analyze an online video game? You will need to make a screencast video and save it on your computer, and then import that video file (recommend MP4 video) into Tracker or Logger Pro. The easiest way to make a screencast video is Screencast-o-matic.