Physics
Mr. Proodian
Period:______________
Name:_______________
Date:________________
Unit Conversions/Scientific Notation Homework /Significant digits
Convert the following: (Answers are in ()’s and are for the exponent of the answer ONLY.
Example: The answer to #1 is 3.45 x 10 3m)
1. 3.45 Km to m (3)
10. 3.45 x 105 mm to cm (4)
2. 4.87 m to Km (-3)
11. 5.78 x 108 cm to Km (3)
3. 1.87 m2 to Km2 (-6)
12. 6.87 x 10-2 cm to mm (-1)
2
2
4. 4.79 Km to m (6)
13. 8.90 x 10-5 mm to Km (-11)
5. 8.97 mm to cm (-1)
14. 9.00 x 10-12 mm2 to Km2 (-24)
6. 9.08 mm to dm (-2)
15. 4.56 x 10-15 cm2 to m2 (-19)
2
2
7. 8.67 cm to Km (-10)
8. 7.54 Km3 to pm3 (45)
9. 5.90 mm to Km (-6)
(Page 18 in your Text)
Scientific Notation:
If a number is written in scientific notation, change it into a decimal number. If a number is written as a
decimal number, change it into scientific notation in standard form (eg. 1.23 x 103). Round any decimal
numbers to the correct number of significant digits when you put it in scientific notation. (Answers in ()’s)
31. 4.56 x 105
(456000)
40. 6780000
(6.78x106)
-5
32. 3.45x 10
(0.0000345)
41. 598201
(5.98201x105)
33. 44.6 x 105
(4460000)
42. 0.0000236 (2.36x10-5)
34. 12.3x 10-5
(0.000123)
43. 0.0980
(9.80x10-2)
35. 136 x 103
(136000)
44. 9.76
(9.76x100)
-3
36. 187 x 10
(0.187)
45. 0.00000000000003769 (3.769x10 -14)
-2
37. 154323 x 10 (1543.23)
DON’T JUST DO THESE IN YOUR HEAD!
38. 25433 x 10-2 (254.33)
PUT PENCIL TO PAPER!
39. 4.56 x 100
(4.56)
There is no textbook help on this section. (sorry)
Scientific notation with division and multiplication:
Multiply or divide the following problems dealing with scientific notation. All answers are to be in
scientific notation with only one significant digit. Notice that all of these must have only one sig fig in
their answer because that is the least in all of the problems! (again, there are no textbook examples)
46. 10 x 1015/5.00 x 105
47. 10 x 10-15/5.00 x 105
48. 10 x 10-15/5.00 x 10-5
49. 40 x 10-5/20 x 1010
50. 40 x 10-5/4.56 x 10-10
(2x1010)
(2x10-20)
(2x10-10)
(2x10-15)
(9x105)
51. (5 x 105) (2 x 105)
52. (5 x 10-5) (2 x 10-5)
53. (8 x 10-5) (10 x 105)
54. (2 x 1015) (10 x 10-20)
55. (9 x 10-8) (10 x 10-10)
(1x1011)
(1x10-9)
(8x101)
(2x10-4)
(9x10-17)
Complete practice problems on page 20 &21, #1-5
Significant Digits: (Sometimes these are called “sig figs” for short)
How many significant digits are in the following numbers? Make sure you know all of the rules for
significant digits before any test or quiz.
16. 100
24. 765.0
17. 1000
25. 0.765
18. 1000.0
26. 0.0000203
19. 101
27. 0.002000
20. 100.
28. 0.100020
21. 0.00001
29. 200 x 10-3
22. 0.001
30. 450 x 10-5
23. 100.00001
See p. 26 of textbook for sig fig rules and for
rules on rounding numbers.
Also, do Practice Problems 15 & 16