This comparative study investigated the effect of supplementing problem-based learning (PBL) with video resources on students' academic achievement in physics, a unit of simple machines. It was carried out in the Ugandan Government and private lower secondary schools. The quasi-experimental design employed a cluster sampling design with 947 students selected from 12 Sheema District, western Uganda schools. Four belonged to the traditional group, four to the PBL group, and four to the video-based PBL group. In the traditional group, the teacher delivered the content, while in the PBL group, students were organized into groups to discuss and present a problem; in the video-based PBL group, students watched YouTube videos related to the functionality of simple machines as part of the PBL approach. SPSS v.25 was used for analysis. The analysis of variance revealed that all groups showed a positive impact after teaching and learning activities (p < 0.001, d = 2.07). Specifically, students (including those in traditional instruction, PBL alone, and video-based PBL groups) from government schools possessed similar performance both before and after instruction, whereas students from private schools demonstrated more significant (p < 0.001, d = 0.19) improvement after receiving instruction. In conclusion, the results showed that PBL is an effective way of teaching physics despite the type of school when supplemented with video resources. Thus, teachers were recommended to use it in their daily routine.