Estimating Gravitational Field Strength

Saw this on Dan Meyer's 101qs.com this evening. What a great photo to clearly show the gravitational field strength on Earth.  I don't like the term "acceleration due to gravity" as its wrong or at best misleading and incomplete, but that's the subject of another post.

This could make a homework assignment and or a great introduction to Logger Pro's video and photo analysis. Plenty to talk about in terms of estimation (of lengths), center of mass, horizontal velocity, etc.

BTW TinEye Reverse Image Search is a great way to find similar photos or in the case above same photo but different resolution.