Penelitian ini bertujuan untuk meningkatkan kemampuan kognitif dan aktivitas belajar siswa kelas XI MIA 3 SMA Batik 1 Surakarta melalui penerapan model discovery learning pada materi Fluida Dinamis.
Penelitian ini merupakan Penelitian Tindakan Kelas (Classroom Action Research) dengan model Kemmis dan Mc. Taggart, serta model kolaboratif yang dilaksanakan dalam dua siklus. Setiap siklus diawali dengan tahap persiapan dan dilanjutkan dengan tahap pelaksanaan siklus yang terdiri atas perencanaan tindakan, pelaksanaan tindakan, observasi, dan refleksi. Subjek penelitian adalah siswa kelas XI MIA 3 SMA Batik 1 Surakarta Tahun Pelajaran 2014/2015 sebanyak 41 siswa. Data diperoleh melalui kajian dokumen, tes tertulis, observasi, dan wawancara. Teknik analisis data yang digunakan adalah teknik analisis data deskriptif kualitatif.
Berdasarkan hasil penelitian, dapat disimpulkan bahwa (1) Penerapan model discovery learning dapat meningkatkan kemampuan kognitif siswa kelas XI MIA 3 SMA Batik 1 Surakarta pada materi Fluida Dinamis. Ketuntasan belajar siswa mencapai 65,85% pada siklus I dan 80,48% pada siklus II dari Kriteria Ketuntasan Minimum sebesar 75. (2) Penerapan model discovery learning dapat meningkatkan aktivitas belajar siswa kelas XI MIA 3 SMA Batik 1 Surakarta pada materi Fluida Dinamis. Hal ini dapat dilihat dari hasil pengamatan aktivitas belajar pada pra siklus, siklus I dan siklus II. Dari indikator aktivitas yang ditentukan diperoleh hasil sebagai berikut: (a) Siswa memperhatikan penjelasan guru/teman diperoleh hasil pra siklus 46%, siklus I 76%, siklus II 90%, (b) Siswa  membaca buku fisika/LKS diperoleh hasil pra siklus 37%, siklus I 54%, siklus II 78%, (c) Siswa merancang alat dan bahan percobaan diperoleh hasil pra siklus 46%, siklus I 53%, siklus II 81,5%, (d) Siswa melakukan percobaan diperoleh hasil  pra siklus 51%, siklus I 64%, siklus II 91%, (e) Siswa menjawab pertanyaan guru diperoleh hasil pra siklus 42%, siklus I 54%, siklus II 72%, (f) Siswa bertanya kepada guru jika ada hal yang kurang jelas diperoleh hasil pra siklus 5%, siklus I 24%, siklus II 33%, (g) Siswa memberikan pendapat pada saat diskusi kelompok diperoleh hasil pra siklus 0%, siklus I 51%, siklus II 56%, (h) Siswa menanggapi pendapat teman diperoleh hasil pra siklus 0%, siklus I 17%, siklus II 33%, (i) Siswa mencatat materi yang disampaikan oleh guru diperoleh hasil pra siklus 46%, siklus I 71%, siklus II 92,5%, dan (j) Siswa mengerjakan latihan soal diperoleh hasil pra siklus 44%, siklus I 71%, siklus II 89%.

The aims of research are to improve the cognitive ability and learning activity of student at class XI MIA 3 of Batik 1 Senior High School Surakarta by using discovery learning model on subject matter Dynamic Fluid.  
This research was a Classroom Action Research (CAR). It has held in two cycles with Kemmis & Mc. Taggart, and collaborative model. Each cycle was begun with preparation stage then continued to implementation phase that consists of planning, action, observation, and reflection. The research subject was XI MIA 3 students of Batik 1 Senior High School Surakarta on Academic Year 2014/2015 that consists of 41 students. The data was collected through document review, test, observation, and interview to the teacher and students. The techniques of data analysis used  descriptive qualitative analysis.
Based on result this research, it can be concluded that: (1) The application of discovery learning model can improve cognitive ability of student on subject matter Dynamic Fluid at class XI MIA 3 of Batik 1 Senior High School Surakarta. Based on 75 point as standard of minimum completion, the completed learning students were 65,85% at cycle I and 80,48% at cycle II. (2) The application of discovery learning model can improve learning activity of student on subject matter Dynamic Fluid at class XI MIA 3 of Batik 1 Senior High School Surakarta. It can be seen from the implementation of before cycle, cycle I and cycle II. Based on the indicators of activities can be concluded that: (a) Student pay attention to the teacher/friend explanation 46% at before cycle, 76% at cycle I, and 90% at cycle II, (b) Student read physics book/student worksheet 37% at before cycle, 54% at cycle I, and 78% at cycle II, (c) Student arrange tools and materials of experiment 46% at before cycle, 53% at cycle I, and 81,5% at cycle II, (d) Student do the experiment 51% at before cycle, 64% at cycle I, and 91% at cycle II, (e) Student answer the teacher’s question 42%, 54% at cycle I, and 72% at cycle II, (f) Student ask to teacher if there are uncleared explanation 5% at before cycle, 24% at cycle I, and 33% at cycle II, (g) Student give an idea to solve the problem in group discussion 0% at before cycle, 51% at cycle I, and 56% at cycle II, (h) Student give opinion and comment for a friend opinion 0% at before cycle, 17% at cycle I, and 33% at cycle II, (i) Student write the object matter which has explained by teacher 46% at before cycle, 71% at cycle I, and 92,5% at cycle II, (j) Student do the exercise 44% at before cycle, 71% at cycle I, and 89% at cycle II.