Chapter 1 Chapter 1 Test Study Guide The test is worth 50 points. - Multiple Choice (13 worth 1 pt. each) - Matching (25 worth 1 pt. each) - Problems ( 2 worth 6 pts. Each) What is Physics? Graphing Data - the parts of a graph - calculate the slope of a line - types of relationships (linear, inverse, quadratic) - extrapolation, interpolation Chapter 1 Chapter 1 Test Study Guide Math Toolkit - SI prefixes - scientific notation - factor-label method - significant figures Measurement - accuracy and precision Section 1.1 Chapter Summary Mathematics and Physics Physics is the study of matter and energy and their relationships. Dimensional analysis is used to check that an answer will be in the correct units. The result of any mathematical operation with measurements never can be more precise than the least-precise measurement involved in the operation. Section Chapter Summary 1.2 Measurement New scientific findings must be reproducible; that is, others must be able to measure and find the same results. All measurements are subject to some uncertainty. Precision is the degree of exactness with which a quantity is measured. Scientific notation shows how precise a measurement is. Accuracy is the extent to which a measurement matches the true value. Section Chapter Summary 1.3 Graphing Data Data are plotted in graphical form to show the relationship between two variables. The line that best passes through or near graphed data is called the line of best fit. It is used to describe the data and to predict where new data would lie on the graph. Section Chapter Summary 1.3 Graphing Data A graph in which data points lie on a straight line is a graph of a linear relationship. In the equation, m and b are constants. The slope of a straight-line graph is the vertical change (rise) divided by the horizontal change (run) and often has a physical meaning. Section Chapter Summary 1.3 Graphing Data The graph of a quadratic relationship is a parabolic curve. It is represented by the equation below. The constants a, b, and c can be found with a computer or a graphing calculator; simpler ones can be found using algebra. The graph of an inverse relationship between x and y is a hyperbolic curve. It is represented by the equation below, where a is a constant. Chapter 1 Chapter Assessment Questions Question 1 How will you express 1 nm in m? A. 1×10-3 m B. 1×10-6 m C. 1×10-9 m D. 1×10-1 m Answer: C Reason: 1 nm is read as 1 nanometer. Here, the prefix nano stands for 10-9 m. Chapter 1 Chapter Assessment Questions Question 2 Multiply the following numbers and write the answer in the least significant digits: 12.3 x 1.2 x 123. A. 1815.48 B. 1.8 × 103 C. 1815 D. 1.82 × 103 Answer: B Reason: The rule for multiplication tells us to the fewest number of sig figs. Here it is two. Chapter Chapter Assessment Questions 1 Question 3 Convert 3.650 into 2 significant digits. A. 3.7 B. 3.6 C. 3.65 D. 0.360 × 101 Answer: A Reason: The last reported digit would be the 6. The digit to the right is a 5. Therefore, we round up. Chapter 1 Chapter Assessment Questions Question 4 If 15 different individuals perform an experiment, and 15 answers are obtained, which answer will be accepted as the most accurate? A. The answer obtained by the maximum number of persons. B. The eighth number if all the numbers are arranged in an ascending order. C. The answer most nearer to the expected answer. D. The average of all the 15 answers. Answer: C Reason: Accuracy describes how well the result of a measurement agrees with the real value. Chapter Chapter Assessment Questions 1 Question 5 A quadratic relationship between two variables is written as ____. A. B. C. D. Answer: B Reason: Quadratic relationship between two variables is y = ax2 + bx + c. Chapter 1 Standardized Test Practice Multiple Choice 1. Two laboratories use radiocarbon dating to measure the age of two wooden spear handles found in the same grave. Lab A finds an age of 2250 40 years for the first object; lab B finds an age of 2215 50 years for the second object. Which of the following is true? A. Lab A’s reading is more accurate than lab B’s. B. Lab A’s reading is less accurate than lab B’s. C. Lab A’s reading is more precise than lab B’s. D. Lab A’s reading is less precise than lab B’s. Answer: C (closer grouping) Chapter Standardized Test Practice 1 Multiple Choice 2. Which of the following is equal to 86.2 cm? A. 8.62 m B. 0.862 mm C. 8.62×10-4 km D. 862 dm Answer: C Chapter Standardized Test Practice 1 Multiple Choice 3. What is the slope of the graph? A. 0.25 m/s2 B. 0.4 m/s2 C. 2.5 m/s2 D. 4.0 m/s2 Answer: A Chapter Standardized Test Practice 1 Multiple Choice 4. Which formula is equivalent to A. B. C. D. Answer: A Chapter 1 Standardized Test Practice Extended Answer 5. You want to calculate an acceleration, in units of m/s2, given a force, in N, and the mass, in g, on which the force acts. (1 N = 1 kg·m/s2) A. Rewrite the equation F = ma so a is in terms of m and F. B. What conversion factor will you need to multiply by to convert grams to kilograms? C. A force of 2.7 N acts on a 350-g mass. Write the equation you will use, including the conversion factor, to find the acceleration. Chapter 1 Standardized Test Practice Extended Answer : Solution 5. You want to calculate an acceleration, in units of m/s2, given a force, in N, and the mass, in g, on which the force acts. (1 N = 1 kg·m/s2) A. Rewrite the equation F = ma so a is in terms of m and F. a = f m Chapter Standardized Test Practice 1 Extended Answer : Solution 5. You want to calculate an acceleration, in units of m/s2, given a force, in N, and the mass, in g, on which the force acts. (1 N = 1 kg·m/s2) B. What conversion factor will you need to multiply by to convert grams to kilograms? 1 kg 1000 g Chapter Standardized Test Practice 1 Extended Answer : Solution 5. You want to calculate an acceleration, in units of m/s2, given a force, in N, and the mass, in g, on which the force acts. (1 N = 1 kg·m/s2) C. A force of 2.7 N acts on a 350-g mass. Write the equation you will use, including the conversion factor, to find the acceleration. a = 2.7 kg· m/s2 350 g a = 7.7 m/s2 1000 g 1 kg Chapter 1 Standardized Test Practice Multiple Choice 6. Find an equation for a line of best fit for the data shown below. Chapter Standardized Test Practice 1 Multiple Choice : Solution 6. Find an equation for a line of best fit for the data shown below. • “Eyeball” line of best fit. • y = mx + b • m is about -6/7 • b can be extrapolated to about 11 y = - 6 t + 11 7 Chapter 1 Standardized Test Practice Test-Taking Tip Skip Around if You Can You may want to skip over difficult questions and come back to them later, after you’ve answered the easier questions. This will guarantee more points toward your final score. In fact, other questions may help you answer the ones you skipped. Just be sure you fill in the correct ovals on your answer sheet.