The purpose of this study was (1) to investigate the effectiveness of the flipped-classroom approach, when coupled with problem-based learning and cooperative learning, compared to that of a traditional classroom; (2) to investigate the effects of watching videos and of doing homework on achievement in a physics course; and (3) to evaluate students' perception of the use of the flipped-classroom format in a physics course. In this study, both qualitative and quantitative data were collected. A pre-test/post-test quasi-experimental method with a control group was used. The results showed that homework performance and the amount of video watched (preliminary work before class) were significantly more effective for student achievement in the flipped-classroom. Moreover, although students struggled to adapt to the new system at the beginning, students who know and feel responsible for their own learning can close the gap with more individual and group activities and can achieve higher grades. (C) 2016 Elsevier Ltd. All rights reserved.