函數(shù)模型及其應(yīng)用

1、函數(shù)模型及其應(yīng)用 1.如何構(gòu)建合適的函數(shù)模型？ 1.下表是某種車的車速與剎車后的停車距離。車速車速km/h101530405060708090100停車距離m471218253443546680（1）根據(jù)上表數(shù)據(jù)，建立車速和剎車后停車距離間的函數(shù)關(guān)系。7374. 21256. 00064. 02xxy 思考、討論： 請(qǐng)根據(jù)你得到的模型，試解釋為什么中華人民共和國(guó)道路交通安全法規(guī)定：機(jī)動(dòng)車在高速公路上行駛，車速超過每小時(shí)100公里時(shí)，安全車距為100米以上；車速低于每小時(shí)100公里時(shí)，最小安全車距不得少于50米？你對(duì)高速公路管理部門有什么新的建議？ 2Some Chemistry student

2、s measured the concentration of chlorine remaining in a swimming pool over a period of 8 hours on a hot summer day. Chlorine had been placed in the pool at 8 am. Their results were as follows.MorningAfternoonTime91011121234Chlorine concentration(ppm)5.03.82.92.21.61.20.90.7a. Use the calculator to f

3、ind the relationship between the chlorine concentration and the time elapsed since the chlorine was placed in the pool.b. Whats the concentration of chlorine had been placed at 8 am ?tey28. 072. 60tppmy72. 6LetThe concentration of chlorine had been placed is 6.72ppm小結(jié)：1.如何構(gòu)建合適的函數(shù)模型？步驟：1.畫散點(diǎn)圖2.利用判斷模型

4、的適用性 越接近于1，模型越合適。3.寫出函數(shù)解析式2R2R2. 函數(shù)模型的應(yīng)用ExampleSome Chemistry students measured the concentration of chlorine remaining in a swimming pool over a period of 8 hours on a hot summer day. Chlorine had been placed in the pool at 8 am. Their results were as follows.MorningAfternoonTime91011121234Chlorine

5、 concentration(ppm)5.03.82.92.21.61.20.90.71.Use the calculator to find the relationship between the chlorine concentration and the time elapsed since the chlorine was placed in the pool.2.Use the results to find the concentration that would be needed at 8 am on a similar day to ensure that the chlo

6、rine concentration did not fall below 1.5ppm (parts per million) before 3 pm.3.If two chlorine doses were used , one at 8 am and another at 12 noon, what concentrations would be needed at these times to ensure that the concentration did not fall below 1.5 ppm before 3 pm.4.What are the implication o

7、f your answers for the effective chlorination of pools at lowest cost?ExampleSome Chemistry students measured the concentration of chlorine remaining in a swimming pool over a period of 8 hours on a hot summer day. Chlorine had been placed in the pool at 8 am. Their results were as follows.MorningAf

8、ternoonTime91011121234Chlorine concentration(ppm)5.03.82.92.21.61.20.90.71.Use the calculator to find the relationship between the chlorine concentration and the time elapsed since the chlorine was placed in the pool.2.Use the results to find the concentration that would be needed at 8 am on a simil

9、ar day to ensure that the chlorine concentration did not fall below 1.5ppm (parts per million) before 3 pm.3.If two chlorine doses were used , one at 8 am and another at 12 noon, what concentrations would be needed at these times to ensure that the concentration did not fall below 1.5 ppm before 3 p

10、m.4.What are the implication of your answers for the effective chlorination of pools at lowest cost?ExampleSome Chemistry students measured the concentration of chlorine remaining in a swimming pool over a period of 8 hours on a hot summer day. Chlorine had been placed in the pool at 8 am. Their res

11、ults were as follows.MorningAfternoonTime91011121234Chlorine concentration(ppm)5.03.82.92.21.61.20.90.71.Use the calculator to find the relationship between the chlorine concentration and the time elapsed since the chlorine was placed in the pool.2.Use the results to find the concentration that woul

12、d be needed at 8 am on a similar day to ensure that the chlorine concentration did not fall below 1.5ppm (parts per million) before 3 pm.3.If two chlorine doses were used , one at 8 am and another at 12 noon, what concentrations would be needed at these times to ensure that the concentration did not

13、 fall below 1.5 ppm before 3 pm.4.What are the implication of your answers for the effective chlorination of pools at lowest cost?ExampleSome Chemistry students measured the concentration of chlorine remaining in a swimming pool over a period of 8 hours on a hot summer day. Chlorine had been placed

14、in the pool at 8 am. Their results were as follows.MorningAfternoonTime91011121234Chlorine concentration(ppm)5.03.82.92.21.61.20.90.71.Use the calculator to find the relationship between the chlorine concentration and the time elapsed since the chlorine was placed in the pool.2.Use the results to fi

15、nd the concentration that would be needed at 8 am on a similar day to ensure that the chlorine concentration did not fall below 1.5ppm (parts per million) before 3 pm.3.If two chlorine doses were used , one at 8 am and another at 12 noon, what concentrations would be needed at these times to ensure

16、that the concentration did not fall below 1.5 ppm before 3 pm.4.What are the implication of your answers for the effective chlorination of pools at lowest cost?1. If the concentration of chlorine have been placed at the beginning is m ppm, whats the concentration of chlorine after t hours? 如果一開始投入m

17、ppm 氯，那么t hours 氯的濃度為多少？2.Use the results to find the concentration that would be needed at 8 am on a similar day to ensure that the chlorine concentration did not fall below 1.5ppm(parts per million) before 3 pm. 一開始需要投入多少濃度的氯，才能確保3pm 前氯的濃度不低于1.5ppm 3.What concentration would be needed at 8 am that

18、 the concentration did not fall below 1.5 ppm before 12 noon? 一開始需要投入多少濃度的氯，才能確保12 noon 前氯的濃度不低于1.5ppm 4.If two chlorine doses were used , one at 8 am and another at 12 noon, what concentrations would be needed at these times to ensure that the concentration did not fall below 1.5 ppm before 3 pm. 兩

19、次分別需要投入多少濃度的氯，才能確保3pm前氯的濃度不低于1.5ppm1. If the concentration of chlorine have been place at the beginning is m ppm, whats the concentration of chlorine after t hours? 如果一開始投入m ppm 氯，那么t hours 氯的濃度為多少？tmey28. 02.Use the results to find the concentration that would be needed at 8 am on a similar day to

20、ensure that the chlorine concentration did not fall below 1.5ppm(parts per million) before 3 pm. 一開始需要投入多少濃度的氯，才能確保3pm 前氯的濃度不低于1.5ppm 7t728. 05 . 1 meppmem115 . 1728. 0The concentration of chlorine is 11ppm. 3.What concentration would be needed at 8 am that the concentration did not fall below 1.5 ppm before 12 noon? 一開始需要投入多少濃度的氯，才能確保12 noon 前氯的濃度不低于1.5ppm 4t428. 05 . 1 meppmem6 . 45 . 1428. 0The concentration of chlorine had been placed is 4.6ppm。 4.