Modeling dynamic of life. Calculus and probabilities for life scientists - Adler - Chapter 1.3 Solutions

1–6 Convert the following into the new units.


1. Find 3.4 pounds in grams (1 ounce is 28.35 grams and 1 pound is 16 ounces).
Get 1.3.1 exercise solution

2. Find 1 yard in mm (1 in. is 25.40 mm and 1 yard is 36 in.).
Get 1.3.2 exercise solution

3. Find 60 years in hours (1.0 year ˜ 365.25 days).
Get 1.3.3 exercise solution

4. Find 65 miles per hour in centimeters per second.
Get 1.3.4 exercise solution

5. Find 2.3 grams per cubic centimeter in pounds per cubic foot.
Get 1.3.5 exercise solution

6. Find 9.807 m/sec\cf0 cf2 2 (the acceleration of gravity) in miles per hour per second.
Get 1.3.6 exercise solution

7-10 Compute the answers by adding the given quantities.


7. A boy who is 1.34 meters tall grows 2.3 cm.
Get 1.3.7 exercise solution

8. After waiting for 1.2 hours for a plane flight, you are told you will have to wait another 17 minutes. What is the total wait?
Get 1.3.8 exercise solution

9. You purchase 6 apples that weigh 145 g each, and 7 oranges that weigh 123 g each. What is the total weight if you add the apples to the oranges?
Get 1.3.9 exercise solution

10. The density of the apples in the previous problem is 0.8 g/cm 3 and the density of the oranges is 0.95 g/cm 3 . What is the total volume if you add the apples to the oranges?
Get 1.3.10 exercise solution

11-14 Figure out which of the following is larger.


11. The area of a square with side length 1.7 cm or of a disk with radius 1.0 cm.
Get 1.3.11 exercise solution

12. The perimeter of a square with side length 1.7 cm or of a circle with radius 1.0 cm.
Get 1.3.12 exercise solution

13. The volume of a sphere with radius 100 m or of a 50 cm deep lake with an area of 3.0 square km.
Get 1.3.13 exercise solution

14. The surface area of a sphere with radius 100 m or the surface area of a lake with area 3.0 square km.
Get 1.3.14 exercise solution

15-18 Find the dimensions of the following quantities.


15. Pressure (force per unit area)
Get 1.3.15 exercise solution

16. Energy (force times distance)
Get 1.3.16 exercise solution

17. The rate of change of the area of a colony of bacteria growing on a plate.
Get 1.3.17 exercise solution

18. The force of gravity between two objects is equal to Gm 1 m 2 /r 2 where m 1 and m 2 are the masses of the two objects, and r is the distance between them. What are the dimensions of the gravitational constant G?
Get 1.3.18 exercise solution

19-22 Check whether the following formulas are dimensionally consistent.


19. Distance = rate times time.
Get 1.3.19 exercise solution

20. Velocity = acceleration times time.
Get 1.3.20 exercise solution

21. Force = mass times acceleration.
Get 1.3.21 exercise solution

22. Energy = 1/2 mass times the square of velocity (see Exercise 16 for the units of energy).
Get 1.3.22 exercise solution

23-26 Using the graph of the function g ( x ), sketch a graph of the shifted or scaled function, say which kind of shift or scale it is, and compare with the original function.


23. 4g ( x )
Get 1.3.23 exercise solution

24. g ( x )- 1
Get 1.3.24 exercise solution

25. g ( x /3)
Get 1.3.25 exercise solution

26. g ( x + 1)
Get 1.3.26 exercise solution


27-30 Find the volumes of the following two cartoon trees (drawing a sketch can help) assuming that the height of the first is 23.1 m and that the height of the second is 24.1 m. What is the ratio of the volume of the larger tree to that of the smaller tree?


27. A tree is a perfect cylinder with radius 0.5 m no matter what the height (the volume of a cylinder with height h and radius r is p hr 2 ).
Get 1.3.27 exercise solution

28. A tree is a perfect cylinder with radius equal to 0.1 times the height.
Get 1.3.28 exercise solution

29. A tree looks like the tree in Exercise 27 , but with half the height in the cylindrical trunk and the other half in a spherical blob on top.
Get 1.3.29 exercise solution

30. A tree looks like the tree in Exercise 27 , but with 90% of the height in the cylindrical trunk and the remaining 10% in a spherical blob on top.
Get 1.3.30 exercise solution

 31-34 Find the mass in kilograms of the following objects.


31. A water bed that is 2 m long, 20 cm thick, and 1.5 m wide. The density of water is 1.0 g/cm 3 .
Get 1.3.31 exercise solution

32. A spherical cow with diameter 1.3 m and density 1.3 g/cm 3 .
Get 1.3.32 exercise solution

33. A coral colony of 3200 individuals each weighing 0.45 g.
Get 1.3.33 exercise solution

34. A circular colony of mold with diameter of 4.8 cm and density of 0.0023 g/cm 2 .
Get 1.3.34 exercise solution

35-38 Change the units in the following functions, and compare a graph in the new units with the original units.


35. (Based on Section 1.2, Exercise 45 ) The number of bees b on a plant is given by b = 2 f + 1 where f is the number of flowers. Suppose each flower has 4 petals. Graph the number of bees as a function of the number of petals.
Get 1.3.35 exercise solution

36. The number of cancerous cells c as a function of radiation dose r is c = r - 4 for r (measured in rads) greater than or equal to 5, and is zero for r less than 5 (as in Section 1.2, Exercise 46 ). Suppose that radiation is instead measured in millirads (1 rad = 1000 millirads).
Get 1.3.36 exercise solution

37. Insect development time A (in days) obeys A = 40 - T/ 2 where T represents temperature in °C for °C between 10 and 40 (as in Section 1.2, Exercise 47 ). Suppose that development time is measured in hours.
Get 1.3.37 exercise solution

38. Tree height h (in meters) follows the formula where a represents the age of the tree in years (as in Section 1.2, Exercise 48 ). Suppose that tree age is measured instead in decades.
Get 1.3.38 exercise solution

39-44 Estimate the following.


39. The speed of light in cm per ns (10 -9 seconds or one nanosecond) (the speed of light is about 186,000 miles/second). A fast computer takes about 0.3 ns per operation. How far does light travel in the time required by one operation?
Get 1.3.39 exercise solution

40. Estimate the speed that your hair grows in miles per hour. (This problem was borrowed from the book Innumeracy .)
Get 1.3.40 exercise solution

41. The weight of the earth in kilograms. The earth is approximately a sphere with radius 6500 km and density 5 times that of water.
Get 1.3.41 exercise solution

42. Suppose a person eats 2000 Kcal per day. Using the facts that 1 Kcal is approximately 4.2 Kj (a kilojoule is a unit of energy equal to 1000 joules) and 1 watt is one joule per second (a unit of power), about how many watts does a person use?
Get 1.3.42 exercise solution

43. If a movie is about 2 hours long, how many movies could you watch if you spent half your time watching movies for 60 years?
Get 1.3.43 exercise solution

44. The volume of all the people on earth in cubic kilometers. If a large mine is about 3 km across and 1 km deep, would they all fit?
Get 1.3.44 exercise solution

 45-48 The following problems give several ways to estimate the number of cells in your body. A cell is roughly a sphere 10 µ m in radius, where 1 µ m is 10 -6 m.


45. Using the fact that the density of a cell is approximately the density of water and that water weighs 1 g/cm 3 , estimate the number of cells in your body.
Get 1.3.45 exercise solution

46. Estimate your volume in cubic meters by pretending you are shaped like a board. Pretending that cells are cubes 20 µ m on a side, what do you estimate the number of cells to be by this method?
Get 1.3.46 exercise solution

47. The brain weighs about 1.3 kg and is estimated to have about 100 billion neurons and 10 to 50 times as many other cells (glial cells). Is this consistent with our previous estimates?
Get 1.3.47 exercise solution

48. The nematode C . elegans is a cylinder about 1 mm long and 0.1 mm in diameter, consisting of about 1000 cells. Are these cells about the same size as the ones in your body?
Get 1.3.48 exercise solution

49–50 The following problems regard tying string or gift-wrapping our planet, thought of as a sphere with radius 6500 km.


49. How long a piece of string would be required to go around the equator? If the string were made 1.0 meters longer and stretched out all the way around, how high would it be above the surface? Does the result surprise you?
Get 1.3.49 exercise solution

50. How large a piece of shrink-wrap would be required to cover the entire planet? If the wrap were increased in area by 1.0 m 2 and stretched out all around, how high would it be above the surface? Why do you think the result is so different from the previous problem? (Working this out takes a lot of decimal places.)
Get 1.3.50 exercise solution