@article {96, title = {PUPILS{\textquoteright} MENTAL MODELS OF A PULLEY IN BALANCE}, journal = {Journal of Baltic Science Education}, volume = {4}, year = {2005}, month = {October/2005}, type = {Original article}, chapter = {26-34}, abstract = {Pupils from 5th, 7th and 9th grades compared the weight of a small standard mass and a big bag hanging in a pulley at different positions in equilibrium. In all the three age groups the majority (about 70\%) of the pupils stated that the lower hanging bag is heavier. Less than 15\% of the pupils in the 7th and 9th grades understood that the bodies must have the same weight. Pupils{\textquoteright} reasoning was classified into four categories that were interpreted as mental models according to Vosniadou{\textquoteright}s framework theory. Only about 5\% of the seventh graders and 10\% of the ninth graders seem to grasp the scientific model Motion that leads to the concept of gravity.}, keywords = {conceptual change, mental model, physics education, secondary school, weight}, issn = {1648-3898}, url = {http://oaji.net/articles/2016/987-1481284915.pdf}, author = {Olavi Hakkarainen and Maija Ahtee} }