Name: Intermediate Algebra Unit 3 Activity 7: Power Functions Due Date: Draft 4/17/06 Why: This activity focuses on power functions. We will not study power functions in depth. Instead this will be an opportunity for you to apply the skills you have obtained this semester in problem-solving, communicating, applying mathematical reasoning to new settings, and using tables, graphs, and equations to answer questions. Obviously, we cannot cover every type of function that you are likely to encounter when using mathematics in your other courses or on the job. So it is important for you to leave Math 30 with the ability to think through new scenarios. Learning Outcomes: 1. Communication: Write clear, organized, and logical solutions with correct notation. Interpret the meaning of solutions in the context of problem situations. 2. Problem-solving: apply the problem-solving process to problems that differ from those studied in class. 3. Multiple Representations: Use info given in tabular, graphical, symbolic, and verbal form to solve problems. 4 . Applications and skills: Solve applications of rational equations. Use power function models in applied contexts to make predictions and decisions. 5. Effective Learner: Actively participate in class activities. Problems for Group Discussion: 1. Police sometimes use the formula s = v30 fd to estimate the speed s (in miles per hour) of a car that skidded d feet upon braking. The variable f is the coefficient of friction determined by the kind of road and the wetness or dryness of the road. The following table gives some values of f: Concrete Tar Wet 0.4 0.5 Dry 0.8 1.0 a. How fast was a car going on a concrete road if the skid marks on a rainy day were 80 feet long? b. How fast was a car going on a dry tar road if the skid marks were 100 feet long? c. How long would the skid marks be for a car driving on a wet tar road traveling at 50 mph? d. Solve for d in terms of s and f