Chapter 7.1, Problem 30E

The kinetic energy E of an object varies jointly with the object’s mass m and the square of the object’s velocity v . An object with a mass of 50 kilograms traveling at 16 meters per second has a kinetic energy of 6400 joules. What is the kinetic energy of an object with a mass of 70 kilograms traveling at 20 meters per second?

The data below is the amount of tar and nicotine in a sample of different brands of 100 mm, non-menthol, filtered cigarettes. a) Using the calculator, find a linear regression model that gives the amount of nicotine, N, as a function of the amount of tar, t. Write the function below. N(t)= b) use this model of nicotine to estimate the amount of nicotine in a cigarette if the amount of tar is listed as 21 mg. c) What is the correlation coefficient, r, for this model? r= Tar 5 16 17 13 13 14 9 15 2 15 13 14 15 16 7 17 Nicotine  0.4 1 1.2 0.8 0.8 1 0.8 1 0.2 1.1 0.8 1 0.9 1.1 0.6 1.3

In 1950, the life-expectancy of women was 72 years old. In 1970, it was 75 years. Let E represents the life expectancy and "t" the number of years since 1950 (t = 0 gives 1950 and t= 10 gives 1960). 21. Express a linear function of life expectancy of women to the data points (0, 72) and (20, 75). a. E=3t-72 c. E=3t/20 + 72 b. E= 20t+ 72 d. E=3t+ 72 22. Predict the life expectancy of women in 2003. a. 79.95yrs old b. 81.25yrs. old 23. Predict the life expectancy of women in 2018. a. 71.25yrs. old b. 75.5yrs old c. 82.35yrs. old d. 83.25yrs old c. 82.2yrs old d. 88.6yrs old