1. SCIENTIFIC MEASUREMENT
INTRODUCTION
TO SI UNITS

2. SI units of measurement are used when performing calculations related to scientific investigations.

3. Purpose of measurement: quantify a variable (tell how much) .
ex: mass.

4. Value determined
by measurement must be accompanied by a unit.
ex: grams

5. SI units were adapted from the metric system.
Base units…..
meter……
gram……….
liter…...
Measure
Length
Mass
Volume

6. The units in the
metric system are defined in multiples of 10 from the standard unit.

7. UNIT CONVERSIONS
To convert from one unit to another in the metric system, you multiply and divide.

8. Multiply when changing from a greater unit to a smaller one.

9. Divide when changing from a smaller unit to a larger one.

10. STANDARD SI MEASUREMENTS

11. LENGTH: The SI unit of measurement to determine length is meter (m).

12. The tool of measurement for length is a ruler/meter stick.

13. Length measures
the distance from one point to another.
*1 meter = 3.28 feet.

14. MASS: The SI measurement unit for mass is the gram (g) OR kilogram (kg)

15. The tool of measurement for mass is the balance.

16. Mass measures of
the amount of matter in an object.
*1 kilogram = 2.2 pounds

17. Mass and Weight
The terms mass and weight are sometimes used interchangeably, but they are not the same.

18. [Mass is a property of the object itself and measures the amount of matter in the object.]

19. Weight
Measures gravitational force that attracts an object to the earth (stops it from floating!)

20. WEIGHT: The SI measurement unit for weight is the Newton (N).

21. Weight varies depending on the amount of gravitational force.

22. On Earth a person may weigh 130 pounds (lbs).

23. On the moon the same person would weigh about 1/6th of that amount or 21.66 pounds!

24. Mass does not
vary or change
with location.

25. VOLUME: The SI measurement unit for volume is cubic centimeters (cm3 or cc) or milliliters (mL).

26. For volume simply multiply the length times the height times the width of the object. V = I x h x w

27. A graduated cylinder is used to measure the volume of liquids.

28. A meniscus is the curve of liquid at its surface.

29. Most menisci curve downwards, but a few curve up, depending on the liquid.

30. To read the volume of a liquid:
1.Get eye level with the meniscus

31. 2.Measure from the bottom of the curve if it curves downward

32. 3.Measure from the bottom of the meniscus if it curves upward

33. Reading the meniscus.

34. To determine volume of irregularly shaped objects, the water displacement method is used.

35. To measure volume by water displacement
1. Place an amount of water in a graduated cylinder.
3. The water level will rise.

36. 2. Read the meniscus to measure volume.
3. Add the object.

37. 4. Read the meniscus to measure volume again.

38. 5. To determine the volume of the object, simply subtract the first measurement from the second.

39. Water Displacement Method

40. Density, D, is the mass (m) of an object divided by its volume (V), D = m/V

41. The SI unit for density is kg/m3, or it is expressed g/cm3.

42. Density of two objects of the same material is always the same even if the objects have different masses.

43. For example, a gold
ring and a gold brick both have the same density, because they are both made of gold.

44. The brick contains more matter than the gold ring, it has a greater mass (it is heavier).

45. Density explains
why some things float, and other things sink.

46. Temperature measures how hot or cold something is.

47. All measurements for temperature are taken in degrees.

48. In the metric system, Celsius is used.

49. The SI unit for temperature is Kelvin, and the English unit is Fahrenheit.

50. To convert from one unit to another, use the following formulas:

51. From Fahrenheit to Celsius

52. From Celsius to Fahrenheit
F= 1.8 C + 32

53. From Kelvin to Celsius
C=K

54. From Celsius to Kelvin
K=C

55. Words for TEST # 1 weight SI Units volume length cubic centimeter
milliliter
graduated cylinder
SI Units
length
meter
mass
kilogram

56. Words for TEST # 1 Fahrenheit meniscus Celsius water displacement
Kelvin
meniscus
water displacement
density
temperature