OOBLECK. A Non-Newtonian Fluid. Science Lesson

Transcription

1 OOBLECK A Non-Newtonian Fluid 1

2 A non-newtonian fluid is a fluid whose flow properties are not described by a single constant value of viscosity. In other words, as the pressure against the fluid is changed, the viscosity or the ability to flow changes. 2

3 Many polymer solutions and molten polymers are non- Newtonian fluids, as are many commonly found substances such as ketchup, starch suspensions, paint, blood and shampoo. 3

4 Paint is a non-newtonian fluids that is thicker at normal pressure but becomes thinner when pressure is applied (when it is brushed on). Asnow89 4

5 An inexpensive, non-toxic example of a non-newtonian fluid is a suspension of starch (e.g. cornstarch) in water, sometimes called oobleck or ooze (1 part of water to parts of corn starch. Uncooked imitation custard, a suspension of primarily cornflour, has the same properties. The name oobleck is derived from the Dr. Seuss book Bartholomew and the Oobleck. ( 5

6 An inexpensive, non-toxic example of a non-newtonian fluid is a suspension of starch (e.g. cornstarch) in water, sometimes called oobleck or ooze (1 part of water to parts of corn starch. Uncooked imitation custard, a suspension of primarily cornflour, has the same properties. The name oobleck is derived from the Dr. Seuss book Bartholomew and the Oobleck. 6

7 Start with a large bowl and put in 1 to 2 cups of cornstarch. Add water (with food coloring if you wish for colored Oobleck) at a ratio of 3:4. (For 1 cup of starch use 3/4 cup of water and for 2 cups of starch use 1 1/2 cups of water. ) You may use less water for a thinner fluid. 7

8 This fluid will flow but also has properties of a solid when compressed. In other words it acts like both a solid and a liquid. Some interesting things can be done with Oobleck. 8

9 Daniel Christensen If you put Oobleck on a large sub-woofer speaker and turn the volume up high it will dance on the surface. 9

10 Some people want to be like Oobleck. They want to be one way one day and another way at another time. In other words, they are wishy-washy. Lacking in strength of character or purpose; ineffective; weak in willpower. ( define.php?term=wishy%20washy) 10

11 PETER HAD THIS PROBLEM But when Cephas came to Antioch, I opposed him to his face, because he stood condemned. For before certain men came from James, he was eating with the Gentiles; but when they came he drew back and separated himself, fearing the circumcision party. And the rest of the Jews acted hypocritically along with him, so that even Barnabas was led astray by their hypocrisy. But when I saw that their conduct was not in step with the truth of the gospel, I said to Cephas before them all, If you, though a Jew, live like a Gentile and not like a Jew, how can you force the Gentiles to live like Jews? (Galatians 2:11 14 ESV) 11

12 God wants his people to take a decided position for the right and truth on his side! In the time of Elijah, the prophet asked, How long halt ye between two opinions? (1 Kings 18:21) 12

13 God does not change (Malachi 3:6) and today he is calling us to take a decided stand for him. 13

14 No one can serve two masters, for either he will hate the one and love the other, or he will be devoted to the one and despise the other. (Matthew 6:24) 14

15 We are called to be holy, and we should carefully avoid giving the impression that it is of little consequence whether or not we retain the peculiar features of our faith. Upon us rests the solemn obligation of taking a more decided stand for truth and righteousness than we have taken in the past. The line of demarcation between those who keep the commandments of God and those who do not is to be revealed with unmistakable clearness. We are conscientiously to honor God, diligently using every means of keeping in covenant relation with Him, that we may receive His blessings, the blessings so essential for the people who are to be so severely tried. (Testimonies for the Church, vol. 7, p. 108) 15

16 There must be a decided stand taken by all our ministers and by all who profess to believe the truth, in reference to the low level that some seem inclined to take in regard to their words and their deportment. (Colporteur Ministry, p. 66) 16

17 Many are inquiring, "How am I to make the surrender of myself to God?" You desire to give yourself to Him, but you are weak in moral power, in slavery to doubt, and controlled by the habits of your life of sin. Your promises and resolutions are like ropes of sand. You cannot control your thoughts, your impulses, your affections. The knowledge of your broken promises and forfeited pledges weakens your confidence in your own sincerity, and causes you to feel that God cannot accept you; but you need not despair. (Steps to Christ, p. 47) 17

18 What you need to understand is the true force of the will. This is the governing power in the nature of man, the power of decision, or of choice. Everything depends on the right action of the will. The power of choice God has given to men; it is theirs to exercise. You cannot change your heart, you cannot of yourself give to God its affections; but you can choose to serve Him. You can give Him your will; He will then work in you to will and to do according to His good pleasure. Thus your whole nature will be brought under the control of the Spirit of Christ; your affections will be centered upon Him, your thoughts will be in harmony with Him. (Steps to Christ, p. 47) 18

19 Desires for goodness and holiness are right as far as they go; but if you stop here, they will avail nothing. Many will be lost while hoping and desiring to be Christians. They do not come to the point of yielding the will to God. They do not now choose to be Christians. (Steps to Christ, pp. 47, 48) 19