A simple discussion of the concept of orders of magnitude.

1. Topic 1 – Physical Measurements 1.1 - Orders of Magnitude

6. Two hectares of land = 20000m 2

7. Seconds in a year = 31556926s

8. The atomic clock frequency = 9192631770Hz

10. Now simply add or subtract the numbers

12. 4.1x10 2 + 3.8x10 3 = (4.1 + 38)x10 2 = 42.1x10 2 =4.21x10 3

13. question

14. Find: 6.8x10 99 – 4.5x10 97

16. If multiplying then ADD the exponents; if dividing then SUBTRACT the exponents

18. 1.5x10 -5 x 4.0x10 2 = (1.5 x 4.0)x10 (-5 + 2) =6x10 -3

19. Question

20. Find: 8x10 78 / 5x10 45

23. The speed of light is 299742548ms -1 . Its order of magnitude is ~10 8 ms -1

25. The nuclear diameter of lead

26. The size of visible Universe.

27. The mass of the electron.

28. The mass of the Universe.

29. The age of the Universe.

31. How many times smaller is the nucleus than an atom?

32. 10 -15 / 10 -10 = 10 -5 times smaller OR 5 orders of magnitude.

33. Questions

34. How many times more massive is the Universe than an electron?

35. How many times older is the Universe than the passage of light across an atom? How many times smaller is …?

37. The area of a tennis court

38. The mass of a basketball

39. The height of an average man

40. The mass of an average man

41. The mass of an average car.