Challenges of designing and carrying out laboratory experiments about Newton's second law

Abstract

Experiment is understood as a core activity in science education as well as science in general. Despite many efforts to improve science education in the laboratory, a cookbook style of verification experiments often dominate school science. In this study, we conducted an open laboratory activity that provided students with an opportunity to think about Newton’s second law reflectively. Specifically, students were encouraged to conduct Newton’s second law experiment in a way that was teacher-guided and then they used the same topic to design and conduct their own experiment. As a result, the students demonstrated their challenges in using various creative experimental methods. For example, some students installed a pulley and weight on both sides of a rail to keep the mass and friction coefficient of the cart constant because they thought the friction of the cart to be the main cause of errors. Other students investigated the bidirectional movement of the cart, finding ways to determine the friction and the small tilted angle of rail at the same time. Through the open laboratory activity conducted in this study, students seemed to show understanding of the nature of science. They realized that there is a difference between the law and reality and that even a simple experiment contains many errors and a lot of complex elements. Students also seemed to reflect on what attitude they should take when they experiment in the future. They considered the importance of experimental design and the meaning of experimental processes and good experiments.