Download Presentation
## Rules for Sig Fig

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -

**Objectives**• Interpretdata in tables and graphs, and recognize equations that summarize data. • Distinguishbetween conventions for abbreviating units and quantities. • Usedimensional analysis to check the validity of equations. • Performorder-of-magnitude calculations.**Mathematics and Physics**• Tables, graphs,andequationscan make data easier to understand. • For example, consider an experiment to test Galileo’s hypothesis that all objects fall at the same rate in the absence of air resistance. • In this experiment, a table-tennis ball and a golf ball are dropped in a vacuum. • The results are recorded as a set of numbers corresponding to the times of the fall and the distance each ball falls. • A convenient way to organize the data is to form a table, as shown on the next slide.**Data from Dropped-Ball Experiment**A clear trend can be seen in the data. The more time that passes after each ball is dropped, the farther the ball falls.**Graph from Dropped-Ball Experiment**One method for analyzing the data is to construct a graph of the distance the balls have fallen versus the elapsed time since they were released. The shape of the graph provides information about the relationship between time and distance.**Physics Equations**• Physicists useequationsto describe measured or predicted relationships between physical quantities. • Variablesand other specific quantities are abbreviated with letters that areboldfacedoritalicized. • Unitsare abbreviated with regular letters, sometimes called roman letters. • Two tools for evaluating physics equations aredimensional analysisandorder-of-magnitude estimates.**Equation from Dropped-Ball Experiment**• We can use the following equation to describe the relationship between the variables in the dropped-ball experiment: (change in position in meters) = 4.9 (time in seconds)2 • With symbols, the word equation above can be written as follows: Dy = 4.9(Dt)2 • The Greek letterD(delta) means“change in.”The abbreviationDyindicates thevertical changeina ball’s position from its starting point, andDtindicates thetime elapsed. • This equation allows you toreproduce the graphandmake predictionsabout the change in position for any time.**Chapter 1**Standardized Test Prep Multiple Choice 1. What area of physics deals with the subjects of heat and temperature? A. mechanics B. thermodynamics C. electrodynamics D. quantum mechanics**Chapter 1**Standardized Test Prep Multiple Choice 1. What area of physics deals with the subjects of heat and temperature? A. mechanics B. thermodynamics C. electrodynamics D. quantum mechanics**Chapter 1**Standardized Test Prep Multiple Choice, continued 2. What area of physics deals with the behavior of subatomic particles? F. mechanics G. thermodynamics H. electrodynamics J. quantum mechanics**Chapter 1**Standardized Test Prep Multiple Choice, continued 2. What area of physics deals with the behavior of subatomic particles? F. mechanics G. thermodynamics H. electrodynamics J. quantum mechanics**Chapter 1**Standardized Test Prep Multiple Choice, continued 3. What term describes a set of particles or interacting components considered to be a distinct physical entity for the purpose of study? A. system B. model C. hypothesis D. controlled experiment**Chapter 1**Standardized Test Prep Multiple Choice, continued 3. What term describes a set of particles or interacting components considered to be a distinct physical entity for the purpose of study? A. system B. model C. hypothesis D. controlled experiment**Chapter 1**Standardized Test Prep Multiple Choice, continued 4. What is the SI base unit for length? F. inch G. foot H. meter J. kilometer**Chapter 1**Standardized Test Prep Short Response 13. Determine the number of significant figures in each of the following measurements. A. 0.0057 kg B. 5.70 g C. 6070 m D. 6.070 103 m**Chapter 1**Standardized Test Prep Short Response 13. Determine the number of significant figures in each of the following measurements. A. 0.0057 kg B. 5.70 g C. 6070 m D. 6.070 103 m Answers: A. 2; B. 3; C. 3; D. 4**Chapter 1**Standardized Test Prep Short Response, continued 14. Calculate the following sum, and express the answer in meters. Follow the rules for significant figures. (25.873 km) + (1024 m) + (3.0 102 cm)**Chapter 1**Standardized Test Prep Short Response, continued 14. Calculate the following sum, and express the answer in meters. Follow the rules for significant figures. (25.873 km) + (1024 m) + (3.0 102 cm) Answer: 26 897 m