Ppt Measurements Unit 1

1. MEASUREMENT

2. S.I. UNITS
•Le system International d’unites
•A modification of the older French metric
system.

3. Base Units
Base units are considered so because
they are not derived from any pre-
existing number or formula. We
need to be able to discuss things
like distance, temperature and
time, and we do so by agreeing to a
reliable definition of some basic
(base!) facts.

4. Base Units
•Length

5. Base Units
•Length
Meter

6. Base Units
•Length
Meter
(m)

7. Base Units
•Mass

8. Base Units
•Mass
Kilogram

9. Base Units
•Mass
Kilogram
(kg)

10. Base Units
•Time

11. Base Units
•Time
Seconds

12. Base Units
•Time
Seconds
(s)

13. Base Units
•Temperature

14. Base Units
•Temperature
Kelvin

15. Base Units
•Temperature
Kelvin
(K)

16. Base Units
•Amount of Substance

17. Base Units
•Amount of Substance
mole

18. Base Units
•Amount of Substance
mole
(mol)

19. Base Units
•Electric Current

20. Base Units
•Electric Current
Ampere

21. Base Units
•Electric Current
Ampere
(A)

22. Base Units
•Luminous Intensity

23. Base Units
•Luminous Intensity
candela

24. Base Units
•Luminous Intensity
candela
(cd)

25. Derived Units
•Area

26. First Derivative
•Area
length squared

27. Derived Units
•Area
length squared
(m
2
)

28. Second Derivative
•Volume

29. Second Derivative
•Volume
length cubed

30. Second Derivative
•Volume
length cubed
(m
3
)

31. Derived Units
•Density

32. Derived Units
•Density
mass per unit volume

33. Derived Units
•Density
mass per unit volume
(kg/m
3
)

34. First Derivative
•Speed (velocity)

35. Derived Units
•Speed (velocity)
distance traveled per unit time

36. Second Derivative
•Speed (velocity)
distance traveled per unit time
(m/s)

37. Third Derivative
•Acceleration

38. Third Derivative
•Acceleration
speed changed per unit time

39. Derived Units
•Acceleration
speed changed per unit time
(m/s
2
)

40. Derived Units
•Force

41. Derived Units
•Force
mass times acceleration of an object

42. Derived Units
•Force
mass times acceleration of an object
(kg m/s
2
)

43. Derived Units
•Force
•Note:
(kg m/s
2
) = Newton (N)

44. Derived Units
•Pressure

45. Derived Units
•Pressure
Force per unit area

46. Derived Units
•Pressure
Force per unit area
(kg /m s
2
) or N/m
2

47. Derived Units
•Pressure
Note:
(kg /m s
2
) = N/m
2
= Pascal (Pa)

48. Derived Units
•Energy

49. Derived Units
•Energy
Force times distance traveled

50. Derived Units
•Energy
Force times distance traveled
(kg m
2
/s
2
)

51. Derived Units
•Energy
Note:
(kg m
2
/s
2
) = Joule (J)

52. Other Units to Know About
•Length
–Angstrom (Å) = 10
-10
m

53. Other Units to Know About
•Pressure
Atmosphere (atm) def.- the pressure
exerted by the earth’s armosphere at sea
level on an average day.
torr or mm of Mercury (mmHg) def.-the
pressure exerted by a column of
mercury (Hg) 1 mm high.

54. Other Units to Know About
•Temperature
3 common scales
Fahrenheit
Celsius
Kelvin

55. In the fahrenheit scale, what
is the temperature of
freezing and boiling water?
Temperature

56. Temperature
Freezing Pt Boiling Pt
32 °F 212 °F

57. Other Units to Know About
•Length
–Angstrom (Å) = 10
-10
m
In the Celsius scale, what is
the temperature of freezing
and boiling water?
Temperature

58. Freezing Pt Boiling Pt
32 °F 212 °F
0 °C 100 °C
Temperature

59. In the Kelvin scale, what is
the temperature of
freezing and boiling
water?
Temperature

60. Temperature
Freezing Pt Boiling Pt
32 °F 212 °F
0 °C 100 °C
273.15 K 373.15 K

61. Temperature
•Formulas for converting scales
°C + 273.15 = K
1.8(°C ) + 32 = °F

62. Other units to know about
•Volume
Liter (l) = 1 dm
3
1 l = 1.06 qt
1 ml = 1 cm
3