1. QUANTITY AND MEASUREMENT
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2. Physical Quantity
A quantity which can be measured is called a physical quantity.
(e.g. velocity, mass, length, force, weight, time, etc)
The quantity which can not be measured is not physical quantity.
(e.g., funny, love, feeling, taste, happiness, afraid, collision, sadness etc)
Conclusion, Physical quantity is something which can be measured and it has a unit.

3. Measurement
Measuring is to Compare a physical quantity of an object with a unit of measurement to get the value.

4. UNIT
In the past, people used parts of their body as units of measurement such as cubit, fathoms, span and step.
Those units are not standard and can cause difficulty in communicating them.
In 1960 the metric system was used and officially called the international system or SI Units ( La Systeme International d’Unites)

5. For measuring more or less than one meter you can use prefixes in the table below.
Symbol
Multiplying Factor
Kilo k
1000
103
Hecto h
100
102
Deca da 10
101
Deci d
0.1
10-1
Centi c
0.01
10-2
Mili m
0.001
10-3
Micro
10-6
Nano n
10-9

6. Unit Conversion km hm
dam m dm mm
: 10
x 10 cm

7. EXERCISES
Convert the following readings to the units indicated and then write down to factors of ten:
m = ………………… km
o.5 m =…………. cm
g = ………………… kg
150 g = ………….. mg
s = ……………….. ms
4. 2 m2 = ……………….. mm2
mL = ………….. L
m3 = ……….. cm3

8. Write down seven fundamental quantities on your notebook
Physical quantities divided into:
Fundamental quantities
Derived quantities
1.Fundamental Quantities
Fundamental quantities are quantities which conventionally established by International conference on weight and measurement.
Write down seven fundamental quantities on your notebook

9. The seven fundamental quantities are shown in the table below:
SI Unit
Symbol
Length
meter m
Mass
kilogram kg
Time
second s
Electric current
Ampere A
Temperature
Kelvin K
Amount of subtance
mol
Luminous Intensity
candela cd

10. 2. Derived quantities
Derived quantities are quantities which are derived from the fundamental quantities
Example:
The physical quantity of velocity is derived from Fundamental quantities namely length and time.
The formula is given:
where S = distance (length) (m)
t = time (s)
v = velocity (m/s) S
v = t
Base quantities are said to have base units and derived quantities have derived units. For example, if displacement and time are chosen to be base quantities, then velocity is a derived quantity:

11. Explain, what is the meaning of fundamental quantities?
EXERCISE
Explain, what is the meaning of fundamental quantities?
Mention 3 examples of fundamental quantities and its units on SI.
Explain, what is the meaning of derived quantities?
Mention 3 examples of derived quantities and its units.
Mention quantities are arrange derived quantities below:
Area
Volume
Density

12. SOME EXAMPLES OF DERIVED SI UNITS
Physical Quantity
SI Unit
Symbol
area
square meter m2
volume
cubic meter m3
density
kilogram per cubic meter
kg.m-3
speed
meter per second
m.s-1
acceleration
meter per second squared
m.s-2
concentration
mole per cubic meter
mol.m-3

13. Length Length is represents the distance between two point
SI unit of length: meter - The meter is the distance travelled by light in a vacuum during a time interval of 1/ of a second.

14. Estimate the length of your bench.
Measuring Length
Estimate the length of your bench.
Then check your answer using a meter rule, measuring tape or ruler
My estimate :
Length = …………………….. cm
Using a ruler/meter rule/ measuring tape:
Length =……………………… cm

15. Conclusion My estimate of length………….. (Is/ is not) accurate
We use ……………………… to measure length accurately

16. Measurement of Length
To measure length, we can use rulers, meter rule, a measuring tape, a vernier caliper and a micrometer screw gauge.
Measuring tape
Ruler
The measuring tape and meter rule are use to measure length accurately to 0.1 cm
Vernier calipers
Vernier calipers has an accuracy of 0.01 cm
Micrometer screw gauge
Micrometer screw gauge has an accuracy of cm

17. Some instruments used for measuring length
Length to be measured
Smallest unit of measurement
Measuring tape
Several meters
0.1 cm (or 1 mm)
Meter rule
Several centimeters to 1 meter
0.1 cm ( or 1 mm)
Vernier calipers
Several millimeters to centimeters
0.01 cm (or 0.1 mm)
Micrometer screw gauge
Less than 1 millimeter to about 2 centimeter
0.001 cm (or 0.001mm)

18. The correct way to read the scale on a ruler is shown in figure below.
Parallax error is due to incorrect positioning of your eye when you take measurements.
In order to prevent parallax error, your eyes must be perpendicular to the scale

19. Measure the length, width and thickness of your textbook.
Length = ………….cm
Width = .…………cm
Thickness = …………… cm
Length
Width
Thickness
Science Text Book
2. Using a measuring tape to measure the circumference of a beaker.
Circumference of the beaker =………….. cm

20. Let us find the thickness of a sheet of paper in your textbook.
Number of sheets in the textbook =………
Total Thickness of all the sheets = ……… cm
   
Note: Do not include the covers. Why not?
Conclusion:
Thickness of one sheet = ……………..cm

21. Vernier calipers

22. Vernier Calipers Inside Jaws Depth Gauge Screw Clamp Main Scale
Outside Jaws
Depth Gauge
Vernier Scale
Main Scale
Screw Clamp
4/4/2019

23. How do you read the measurement on a pair of vernier calipers?
Read the main scale marking just before the zero marking of the vernier scale.
This show 4.7 cm
Find the vernier scale marking which is in line with the main scale marking.
This show 0.4 mm
Result = 4.7cm mm = 4.7 cm cm
= 4.74cm
4/4/2019

24. Checking for zero error
Positive zero error
If the zero marking of the vernier scale is to the right of the zero marking on the main scale
Negative zero error
- If the zero marking of the vernier scale is on the left of the zero marking on the main scale
4/4/2019

25. EXERCISE 1. ……………………shows the distance between two points.
2. The SI unit for length is………………………….
3. Look at the figure below !
Write the length pointed by the arrows in the figure!
a…… mm =……cm f. ……mm =……cm
b. ……mm =……cm g. ……mm =……cm
c. ……mm =……cm h. ……mm =……cm
d. ……mm =……cm i . ……mm =……cm
e …… mm =…….cm j. ……mm =……cm

26. Micrometer screw gauge

27. Parts of Micrometer screw Gauge

28. How do you read the measurement on a micrometer screw gauge?
1. Read the marking on the sleeve just before the thimble.
2. Find the thimble scale marking which is in line with the main scale.

30. What is the difference between mass and weight?
The amount of materials in the substance is called mass
The SI unit of mass, the kilogram (kg), is defined as the mass of a specific
platinum–iridium alloy cylinder kept at the International Bureau of Weights
and Measures at Sèvres, France
What is the difference between mass and weight?

31. A spring weighing scaleNo
Mass
Weight 1.
Mass an object is fixed, although the object’s position changes
Weight an object is not fixed if the object’s position change 2.
Mass is not affected by the gravitational force
Weight is affected
by the gravitational force 3.
In SI, mass uses basic unit kilogram
In SI, Weight uses unit is Newton 4.
The mass of an object is measured with lever balance
The weight is measured with
spring balance 5.
Mass is amount of substance of an object
Weight is the force gravitational
an object
A spring weighing scale

32. Instrument to measure mass
Beam balance
Electrical balance

33. Time Time is the duration between two events
The SI unit for time is second.
One standard second is the time needed by Cesium atom to vibrate 9,192,631,770 times
The nation’s primary time standard is a cesium fountain atomic clock developed at the National Institute of Standards and Technology laboratories in Boulder, Colorado.

34. Time Conversion
1 day = 24 hours 1 hour = 60 minutes 1 minute = 60 seconds
For fast event, you can use milisecond (ms), microsecond (µs) and nanosecond (ns)

35. Temperature Degree of hotness of an object.
The SI unit for temperature is Kelvin
The common measuring tool for temperature is thermometer
People know degree Celcius (°C), Fahrenheit (°F) and Kelvin (K) as the scale on thermometer

36. Temperature Conversion
TK = Tc + 273

37. Derived Quantity : Volume and Area
A. Volume
Volume shows the space occupied by an object
The unit of volume is m3
Liter is not the SI unit, but frequently used in our life.
1 dm3 = 1 L

38. MEASUREMENT OF VOLUME DO YOU KNOW, WHAT IS IT ?
It is a measuring Cylinder 10 30 50 70
It is a measuring Cylinder
scale
scale

39. NOW, LOOK AT THIS
stone 10 30 50 70 70 50 30 10
Initial water level (V0) is 30 ml

40. stone 10 30 50 70 70 50 30 10
Initial water level (V0) is 30 ml

41. Thus, the volume of rock is
The formula used to measure the volume of an irregular shaped object is
V = V1 – V0
NOTE :
V = volume of irregular shaped object
V0 = The initial water level
V1 = The final water level 10 30 50 70
stone
Thus, the volume of rock is
50 mL – 30 mL = 20 mL 70 50 30 10
Initial water level (V0) is 30 ml
Final water level ( Vt ) is 50 ml

42. Measuring volume of regular and irregular solid
Please make a report of your activity on your exercise book
Measuring volume of regular and irregular solid
1. Objective:…………..
2. Material:
Cube
Stone
Measuring cylinder
………………. and so on
3. Procedure:
Measure volume regular solid:
……………………………….
………………………………. and so on
Measure volume irregular solid:
……………………………….. and so on
4. Data & Analyze:
Volume of cube:……………cm3
Volume of stone: …………. mL
5. Conclusion:
To measure volume of regular solid we can use…..
To measure volume of irregular solid we can use….

43. Conclusion
To measure the volume of regular solid can be determined by measuring length, width and height.
To measure the volume of irregular solid can be determined by using a measuring cylinder.

44. What is the unit of volume?
How to measure volume of regular-shaped object? Explain.
How to measure volume of irregular-shaped object? Explain.
What is the formula to find volume of regular-shaped? Explain.
What is the formula to find the volume of irregular-shaped object? Explain.

45. Is the amount of space that a flat surface covers.
A. AREA
Is the amount of space that a flat surface covers.
Area is derived quantity which is derived from fundamental quantity namely length.
The SI unit of area is square metre (m2)

46. How to measure area of an object?
For a regular shape:
- can determined by measurement or calculation
rectangle
trapezium a b h a a
width h h
parallelogram b b
circle
length r
A = height x ½ x (a+b)
A = length x width
heigth r r r
A = πr2
A = base x height

47. For irregular shape
Please do activity of measuring areas.

48. Conclusion
To measure the area of regular shape can be determined by measurement or calculation
To measure the of irregular shape can be determined by tracing the object on a sheet of graph paper.