This paper describes an experiment in which a block is pulled by a string across the top of a cart and drags the cart along with it (see Fig. 1). The ratio of the block's displacement to the cart's displacement can be modeled using the algebra-based Newtonian mechanics available to introductory college and advanced high school students. We examined the effect of the mass of the block on this ratio. Displacement data for the block and cart were obtained using video analysis. This experiment was originally conceived of and carried out by students in my honors physics course. We present the results of this experiment. The results are in good agreement with the model derived here.

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