Abstract
Abstract This research is a development research that aims to test the effectiveness of the inquiry model-based core physics learning device with the help of PhET virtual media in improving students’ conceptual understanding. The device was developed using a 4D model which includes define, design, develop and disseminate. The sample of this study was all undergraduate students who took core physics courses which consisted of two classes, namely class A (experimental class) and class B (control class) which amounted to 50 people. The results of the pre-test and post-test were analyzed using the t-test at a significance level of 5%, while the increase in understanding of the concept used the N-gaint test. The results of the t- test show that the t-count value is greater than the t-table. This means that core physics learning tools using an inquiry model with the help of PhET virtual media affect students’ understanding of concepts. Analysis of increasing understanding of the concept of d using the N-gain test. The N-gain analysis shows that students’ understanding of concepts has increased the use of these devices in the high category. This means that students’ understanding of concepts is effectively improved using an inquiry model with the help of PhET virtual media.