美国（USA）高中物理教材原理与问题全册（PDF版）

What You’ll Learn • You will use mathematical tools to measure and predict. • You will apply accuracy and precision when measuring. • You will display and evaluate data graphically. Why It’s Important The measurement and mathematics tools presented here will help you to analyze data and make predictions. Satellites Accurate and precise measurements are important when constructing and launching a satellite— errors are not easy to correct later. Satellites, such as the Hubble Space Telescope shown here, have revolutionized scientific research, as well as communications. Think About This � Physics research has led to many new technologies, such as satellite-based telescopes and communications. What are some other examples of tools developed from physics research in the last 50 years? 2 physicspp.com NASA 002-010 CH01-S1-845813 3/30/04 1:03 AM Page 2 http://physicspp.com Do all objects fall at the same rate? Question How does weight affect the rate at which an object falls? Procedure The writings of the Greek philosopher Aristotle included works on physical science theories. These were a major influence in the late Middle Ages. Aristotle reasoned that weight is a factor governing the speed of fall of a dropped object, and that the rate of fall must increase in proportion to the weight of the object. 1. Tape four pennies together in a stack. 2. Place the stack of pennies on your hand and place a single penny beside them. 3. Observe Which is heaviest and pushes down on your hand the most? 4. Observe Drop the two at the same time and observe their motions. Analysis According to Aristotle, what should be the rate of fall of the single penny compared to the stack? What did you observe? Critical Thinking Explain which of the following properties might affect the rate of fall of an object: size, mass, weight, color, shape. 1.1 Mathematics and Physics � Objectives • Demonstrate scientific methods. • Use the metric system. • Evaluate answers using dimensional analysi