Online teaching of Newton's laws using PhET simulations

Emerging situations such as caused by COVID-19 pandemic, have presented challenges to education at all levels, which require new creative and innovative approaches that enhance the use of available technologies, in order to improve the learning condi-tions of student in extraordinary circumstances. In this context, this paper assesses the learning that generates an instruction of Newton's laws that is supported by PhET simulations, in an online university course during confinement by COVID-19. Instruction efficiency was evaluated through employing of Force Concept Inventory (FCI) before and after of the intervention, the students' perception of their knowledge after the instruction was explored, as well as the type of external representations they manifested. The study revealed a 7.2 % increase in the percentage of correct answers in the FCI test, while 68 % (13/19) of the items presented a lower difficulty index. For their part, 82 % of the students who considered knowing "nothing" before the instruction perceived some kind of improvement, indicating that they knew "little" or "some" after the instruction. Taken together, these observations give a positive assessment of using PhET simulations to support Newton's laws teaching in an online course, opening the possi-bility to the design and develop new simulations that enhance the results obtained.