G7 Scientific Measurements PDF

Introduction ------------ ### 1.1 Scientific Measurements - - - - ### Introduction #### Indigenous Methods of Measurements #### A. Length +-----------------------------------------------------------------------+ | **Activity 1.1:** Make a group containing 5 students. Using your hand |...

Introduction ------------ ### 1.1 Scientific Measurements - - - - ### Introduction #### Indigenous Methods of Measurements #### A. Length +-----------------------------------------------------------------------+ | **Activity 1.1:** Make a group containing 5 students. Using your hand | | span, cubit and digit measure the width of a table or a desk in your | | classroom. Record your measurement in the table below. | | | | ***No*** ***Name of the student making measurement*** ***Measur | | ement result*** | | ---------- ---------------------------------------------- --------- | | ----------------- | | **1** | | **2** | | **3** | | **4** | +-----------------------------------------------------------------------+ #### B. Mass 1. **Weqet-** Weqet is a mass measuring unit usually used to measure 2. **Quntal --** Quntal (may be taken from the English word quintal) is a bag used to measure the mass of grains. It is equal to a hundred kilogram. 3. **Feresula:**- is used to measure the mass of pepper and coffee. It is equal to 17 kilogram.  ##### C. Time ##### D. Volume 1. **Jog:** A plastic cup used for measuring the volume of liquids. 2. **Tassa:** A can used to measure cereals, pulses ,liquids and solids. 3. **Sini:** A small ceramic cup often used for measuring coffee, pulses and spices. 4. **Birchiko:** A glass often for measuring pulses and liquids. 5. **Kubaya:** A mug, often used for measuring cereals, pulses and liquids. 1. Discuss about the problems there could be in using the above indigenous volume measuring devices. 2. Discuss in group about the pros and cons of indigenous measurements used in your locality #### Physical Quantities and Scientific Methods of Measurement #### 1.Fundamental Physical quantities and their units **Table 1. 1 Fundamental quantities and their SI units** **Quantity** **Name of Unit** **Symbol of the unit** ----------------- ------------------ ------------------------ **Length** Meter m **Mass** kilogram kg **Time** Second S **Temperature** Kelvin K #### 2.Derived Physical Quantities and their Units #### Table 1. 2 Derived quantities and their SI units Derived quantity Symbol -- ------------------ -------- ------------------ Area A m x m = m^2^ Volume V m x m x m = m^3^ Speed V m/s Density ~~ῤ~~ Kg/m^3^ a. The equation for the area of rectangular surface is Area = length x width. b. The equation for speed is #### Prefixes and Conversion of Base Units Prefix **Table 1.3. SI prefixes** ------------- -- --------------- ---------- **micro µ** **millionth** 0.000001 ------------- -- --------------- ---------- #### Conversion of base units ? = 200m1000*m* 1000 +-----------------------------------------------------------------------+ | **Exercise 1.5** 1. Convert the following: | | | | a\) 0.6 km to cm b) 500 g to kg c) 30 min to hour | | | | d\) 50 m to mm e) 0.25 kg to g f) 0.5 hour to second 2. Write the | | following quantities in units with the appropriate prefixes: | | | | a\) 3500 m b) 0.0012 sec c) 0.01 g | +-----------------------------------------------------------------------+ #### Measuring Physical Quantities #### Measuring the mass of objects Different types of balances are there, see Fig 1.4. #### Measuring Length #### Solution: 1m = 100 cm = 100 x 10 mm = 1000 mm #### Measuring time  #### Measuring Temperature - measure the body temperature of two students by using thermometer. - Compare the two temperatures with the standard temperature of a body which is 37°C - Discuss about your observations. - #### Accuracy and Precision in Measurement a. accurate but not precise (c) precise but not accurate b. accurate and precise (d) neither precise noraccurate 1. Define the following terms: physical quantity, fundamental quantity, derived quantity. 2. State the various indigenous methods of measurement used in Addis Ababa. 3. What are prefixes? 4. What is the difference between accuracy and precision in measurements? ##### 1.2 Doing Scientific Investigation - describe the components of a scientific investigation; - demonstrate ability to work effectively and respectfully with others in performing fair testing; - practice scientific investigation procedures using appropriate contents to their age levels. #### Introduction to Scientific Investigation ##### 1.2 Scientific Method ##### 1. Ask Questions ##### 2. Perform Background Research ##### 3. Establish your Hypothesis #### 4. Test your Hypothesis ##### 5. Analyze the Results and Draw a Conclusion ##### 6. Communicating Results 1. **Ask Question:** Is air necessary for burning? 2. **Do back ground Research:** From different literatures ''air is necessary for burning.'' 3. **Formulate Hypothesis:** The null hypothesis is that there wil be no air needs for burning. The alternative hypothesis is that there will be air needs for burning. 4. **TestHypothesisby ExperimentandCollectData:** Takeacandle and fix it on a table. Light the candle. The candle will continue to burn due to continuously available fresh air providing the required oxygen for combustion.Now cover the burning candle by putting an inverted gas jar over it. After a short time, the candle stops burning and gets extinguished. 5. **Analyze the Results and Draw Conclusion:** 6. **Communicate Results:** Report your findings in the form of a written report as an oral presentation. Air is necessary for burning. a. What is the effect of sunlight on the growth of bean plant? b. Does a coiled nail act like a magnet? c. How do plants store their food in their leaf? #### Summary - Measurement is the process of obtaining the magnitude of a quantity relative to an agreed standard. - Indigenous units of measurement for length: cubit, span, digit, foot and pace, for mass weqet and quntal, for time length of a shadow are used. - Fundamental quantities are a set of physical quantities which cannot be expressed in terms of any other quantities. Their corresponding units are called "Fundamental units". - The physical quantities which can be obtained by mathematically combining (i.e., multiplying and dividing) the fundamental quantities are known as "Derived quantities". Their corresponding units are called "Derived units". - Prefixes are a short hand form of writing very large or very small numbers. - Accuracy refers to how close a measurement is to the accepted value while precision refers to how close measurements are to each other. - Scientific method is the process by which scientists approach their work. +-----------------------------------------------------------------------+ | I. **Choose the correct answer from the given alternative** | | | | 1. Which of the following quantities is a fundamental quantity? | | | | a. Area b) volume | | | | c\) temperature d) force | | | | 2. The difference between fundamental and derived unit is | | | | b. Fundamental units are big in value but derived units are | | small in value. | | | | c. Fundamental units are derived from derived units. | | | | d. Derived units are derived from fundamental units. | | | | e. There is no difference between them. | | | | 3. Which of the following is a derived quantity? | | | | f. mass b) area | | | | c\) time d) length | | | | 4. The SI unit of density is | | | | g. kg/m^2^ b) kg/m^3^ | | | | c\) kg/m d) g/m^3^ | | | | 5. The prefix that represents is\_\_\_\_\_\_\_\_\_\_. | | | | h. kilo b) mega | | | | c\) centi d) milli | | | | II. **Fill in the blank spaces with an appropriate word.** | | | | 6. Length, mass, time and temperature are | | \_\_\_\_\_\_\_\_quantities. | | | | 7. Area, volume, density and force are \_\_\_\_\_\_\_\_\_\_\_ | | quantities | | | | 8. One million centimeter is equal to \_\_\_\_\_\_\_\_\_\_\_\_\_ | | meter. | | | | 9. The prefix for a number 0.01 is | | \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. | | | | 10. The SI unit of volume is | | \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. | +-----------------------------------------------------------------------+ +-----------------------------------------------------------------------+ | III. **Match the quantities in column-I to their units in | | column-II:** | | | | **Column I** **Column II** | | -- -------------- --------------- | | Area \(a) K | | Temperature (b)m^3^ | | Density (c ) m2 | | Volume (d)kg | | Mass ( e) kg/m3 | | | | IV. **Give short answer** | | | | 1. Write four fundamental quantities with their units. | | | | 2. Write four derived quantities with their units. | | | | 3. Write the measurement 0.005 m using prefix. | | | | 4. Convert 1000 cm to kilometer. | | | | 5. The value of acceleration due to gravity on the surface of | | Earth is known to be 9.81 m/s^2^. In an experiment students | | have found the following results. 12.2 m/s^2^, 12.3 m/s^2^, | | 12.1 m/s^2^ and 12.08 m/s^2^. Is this measurement accurate or | | precise? | | | | 6. List the steps used in scientific method. | +-----------------------------------------------------------------------+  ##### 2.1 Early Thinking about the Composition of Matter +-----------------------+-----------------------+-----------------------+ | | *At the end of this | | | | section, you will be | | | | able to:* | | | | | | | | - Give a short | | | | history of the | | | | concept of the | | | | atom; | | | | | | | | - Compare and | | | | contrast the | | | | continuity and | | | | discreteness | | | | | | | | (discontinuity) | | | | theory of matter; | | | | | | | | - Compare earlier | | | | conceptions of | | | | the structure of | | | | matter with their | | | | conceptions. | | +=======================+=======================+=======================+ | | | | +-----------------------+-----------------------+-----------------------+ 1. What is matter? 2. What do you think matters made up of? a. Group 1: According to Aristotle's believe b. Group 2: According to Democritus's believe ---------------------------------------------- -------------------------------- Proposed by Aristotle  There is a limit to which matter is broken Matter is infinitely divisible Rejected the idea of atoms ---------------------------------------------- --------------------------------