The flipped classroom has been introduced to promote collaborative learning and higher-order learning objectives. In contrast to the traditional classroom, the flipped classroom has students watch prerecorded lecture videos before coming to class and then "class becomes the place to work through problems, advance concepts, and engage in collaborative learning". In this paper, the active flipped learning was applied in engineering mechanics class to combine flipped classroom with active learning in order to establish an active flipped learning (AFL) model, aiming to promote active learning. Eighty sophomores engineering students, most of whom are African-American students, participated the active flipped learning. To compare the effect of AFL, the traditional teaching was applied in the first half semester and pre- and post-tests were used to evaluate their learning performance. After the mid-term exams, five flipped models were applied to five topics. All of the students attended these flipped models. Pre- and post-tests were conducted for the AFL. The survey results were analyzed to compare students' learning self-efficacy and satisfaction between the traditional and the active flipped classroom. Compared to the traditional classroom, students' learning motivation is obviously enhanced in the AFL classroom, with students' interest, curiosity and learning initiatives in curriculum promoted, intrinsic goal orientation further strengthened, in which students tend to have less extrinsic goal orientation and lower test anxiety than the students in the traditional classroom, but with improved control beliefs and self-efficacy for learning. In the traditional classroom, students use more rehearsal and elaboration strategies, while in the flipped classroom, students use more organization strategies and prefer to use critical thinking strategies to raise relative questions about teaching content and video materials. Students in the AFL model use more strategies of resource management, such as time and study environment, effort regulation, peer learning, and help seeking than in the traditional model. In comparison of different student groups, the AFL model effectively improves students' motivation in both long and short learning time groups, but the effects are not obvious on the low GPA students. From the perspective of gender, the AFL model helps to increase the male students' learning motivation, while female students use more learning strategies in task value, control belief and self efficacy in traditional model. Therefore, the instructors should pay more attention in improving the learning motivation and effectiveness of low GPA group and female students in the flipped classroom. In summary, the AFL model, by taking advantage of advanced technology, is a convenient and professional avenue for engineering students to strengthen their academic confidence and self-efficacy in Engineering Mechanics by actively participating in learning and fostering their deep understanding of engineering statics and dynamics.
