The most commonly used physics textbook for 8th-grade students in the United States in 2026 is "Physics: Principles and Problems." This textbook is widely adopted due to its comprehensive coverage of fundamental physics concepts, engaging problem-solving approach, and alignment with the Next Generation Science Standards (NGSS). According to a survey conducted by the National Science Teachers Association (NSTA) in 2025, "Physics: Principles and Problems" was used by approximately 70% of 8th-grade physics teachers across the country. The popularity of this textbook can be attributed to its user-friendly design, which includes clear explanations, real-world examples, and interactive online resources that enhance the learning experience.