Penelitian ini bertujuan untuk meningkatkan hasil belajar siswa melalui penerapan model pembelajaran konstruktivisme (MPK) dengan pendekatan pemecahan masalah (PM). Jenis penelitian ini adalah penelitian tindakan kelas (PTK) yang dilakukan dalam 2 (dua) siklus, setiap siklus terdiri dari tahap perencanaan, pelaksanaan, observasi, dan refleksi. Penelitian ini dilakukan pada siswa kelas XI IPA MAN 3 Lombok Tengah, sebanyak 30 orang. Instrumen penelitian terdiri dari lembar penilaian keterlaksanaan pembelajaran, lembar penilaian aktivitas belajar siswa, dan tes hasil belajar kognitif siswa pada materi getaran dan gelombang. Data dikumpulkan dengan teknik observasi dan teknik tes. Teknik observasi dilakukan untuk mendapatkan data keterlaksanaan pembelajaran dan aktivitas belajar siswa yang dibelajarkan dengan MPK-PM, sedangkan teknik tes digunakan untuk mendapatkan data hasil belajar kognitif siswa. Hasil penelitian menunjukkan pada siklus I, keterlaksanaan pembelajaran rata-rata 2,925 dengan kategori baik, aktivitas belajar siswa rata-rata 2,420 kategori cukup aktif, dan hasil belajar siswa rata-rata 72,650 dengan kategori baik, sedangkan pada siklus II, keterlaksanaan pembelajaran rata-rata 3,291 dengan kategori baik, aktivitas belajar siswa rata-rata 2,985 kategori aktif, dan hasil belajar siswa rata-rata 78,680 kategori sangat baik. Terjadi peningkatan hasil belajar dan aktivitas siswa dari siklus I ke siklus II (86.67 %). Dengan demikian, penerapan MPK-PM dapat meningkatkan hasil belajar siswa kelas XI IPA MAN 3 Lombok Tengah pada pembelajaran fisika materi getaran dan gelombang.Improving Physics Learning Outcomes through the Constructivism Model with a Problem Solving ApproachAbstractThis study aims to improve student learning outcomes through the application of the constructivism learning model (MPK) with a problem solving approach (PM). This type of research is classroom action research (PTK) which is conducted in 2 (two) cycles, each cycle consisting of planning, implementation, observation, and reflection stages. This research was conducted on students of class XI IPA MAN 3 Central Lombok, as many as 30 people. The research instrument consisted of learning implementation assessment sheets, student learning activity assessment sheets, and tests of students' cognitive learning outcomes on vibration and wave material. Data was collected by observation techniques and test techniques. Observation techniques are used to obtain data on the implementation of learning and student learning activities taught by MPK-PM, while test techniques are used to obtain data on students' cognitive learning outcomes. The results showed that in the first cycle, the average learning achievement was 2.925 in the good category, the average student learning activity was 2.420 in the fairly active category, and the average student learning outcomes were 72.650 in the good category, while in the second cycle, the average learning implementation 3,291 in the good category, the average student learning activity is 2,985 in the active category, and the average student learning outcomes are 78,680 in the very good category. There was an increase in student learning outcomes and activities from cycle I to cycle II. Thus, the application of MPK-PM can improve student learning outcomes of class XI IPA MAN 3 Central Lombok in learning physics subject to vibration and waves.