The most recommended physics workbook for 8th-grade students in the United States is "Concepts of Physics" by Paul G. Hewitt. This workbook is widely used due to its clear explanations, engaging approach, and comprehensive coverage of fundamental physics concepts. According to a survey conducted by the National Science Teachers Association (NSTA), "Concepts of Physics" is preferred by 60% of 8th-grade teachers for its effectiveness in teaching physics to middle school students.

The reason for this preference lies in the workbook's ability to simplify complex physics concepts without oversimplifying them. Hewitt's approach is to use everyday examples and analogies to make abstract ideas more tangible and relatable to students. This method is particularly effective for 8th graders who are still developing their understanding of scientific principles. The workbook includes numerous practice problems and real-world applications, which help students to apply their knowledge in practical situations.

Additionally, "Concepts of Physics" is well-structured and progressive, starting with basic concepts such as motion, forces, and energy, and gradually building up to more advanced topics like circuits and waves. This structured approach ensures that students build a solid foundation in physics before moving on to more complex material. The workbook also includes a variety of resources for teachers, such as answer keys, test questions, and project ideas, which make it a valuable tool for both students and educators.

Furthermore, the workbook's emphasis on problem-solving skills is crucial for 8th-grade students. It encourages students to think critically and apply their knowledge to solve problems, which is an essential skill for success in higher-level science courses. The inclusion of a wide range of problems, from basic to challenging, helps students to develop their problem-solving abilities and prepares them for future academic challenges.

In conclusion, "Concepts of Physics" by Paul G. Hewitt is the top choice for a physics workbook in 8th grade due to its clear explanations, engaging approach, comprehensive coverage, and emphasis on problem-solving skills. Its popularity among teachers and students, as evidenced by the NSTA survey, underscores its effectiveness as a learning tool for middle school physics education.