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← 10x-05 Under Pressure

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Showing Revision 1 created 11/04/2012 by podsinprint_user1.

  1. So, what are the consequences of something
  2. being placed under pressure? Well, if I look
  3. at this balloon, I can apply pressure to it by
  4. exerting a force over its area. And when I do,
  5. well, the balloon actually gets a little bit
  6. smaller. The air inside the balloon gets a
  7. little more densely packed together. And
  8. in fact, this is exactly what happens on earth.
  9. Out here, far away from the surface of the
  10. earth, there are not very many air molecules.
  11. This is a low pressure environment and
  12. with nothing to weigh down on these air
  13. molecules from above, they’re basically
  14. free to play. They are free to move around.
  15. Now below this outer layer of the
  16. atmosphere, where all these air molecules
  17. are sort of weighing on the atoms below it,
  18. the molecules below it, and so these become
  19. a little more densely packed. And as we go
  20. even further down towards the surface of
  21. the earth, where us humans tend to live,
  22. the air gets even more densely packed.
  23. And so we see that down near the surface
  24. of the earth, where we have high pressure,
  25. we also have a high density of air molecules.
  26. And this high density of air molecules makes
  27. us humans living at the surface very happy.
  28. So I want to know, why do humans like high
  29. pressure so much? Maybe the weight from
  30. all that air above us keeps us from growing
  31. too tall. Maybe air pollution tends to go to
  32. regions of low pressure. Or maybe it means
  33. that there’s lots of oxygen for us to breathe.
  34. Go ahead and choose the best answer.