Scientific Learning
Test Your Concept:
1. Fill in the blanks with suitable words:
a) The quantity of matter contained in a body is called mass.
b) The duration between two events is called time.
c) One day is equal to 24 hours/1440 minutes/86,400 seconds.
d) The standard unit of mass is Kilogram (kg).
e) The instrument which is used to measure time is digital watch/automatic watch/pendulum clock.
f) By interpreting the experimental findings acceptable conclusion can be drawn.
2. Tick (✓) the correct alternatives (MCQs):
a) Which of the following is the standard unit of mass?
A. pau
B. kilogram (✓)
C. metric ton
D. dharni
b) How many metres are there in one kilometre?
A. 100 m
B. 10000 m
C. 1000 m (✓)
D. 500 m
c) What is the SI unit of temperature?
A. kelvin (✓)
B. celsius
C. fahrenheit
D. calorie
d) Which one is equal to one day?
A. 8,600s
B. 48,600s
C. 68,400s
D. 86,400s (✓)
e) Which skills draws conclusions from observation or information gathered?
A. processes
B. inferring
C. communication
D. analysis (✓)
f) What is SI unit of volume?
A. m³ (✓)
B. cm³
C. m²
D. km³
3. Match the following:
| Column 'A' | Column 'B' |
|---|---|
| temperature | metre |
| length | cubic metre |
| time | kelvin |
| area | second |
| volume | square metre |
Answer:
| Column 'A' | Column 'B' |
|---|---|
| temperature | kelvin |
| length | metre |
| time | second |
| area | square metre |
| volume | cubic metre |
4. Short answer questions.
a) What is called the quantity which can be measured?
Answer: The quantity which can be measured is called physical quantity.
#What do you mean by physical quantity?
b) Define measurement.
Answer: Measurement is the process of comparing an unknown physical quantity with a standard known quantity.
Or,
The process of finding the unknown quantity of an object or system by comparing it with a standard quantity is called measurement.
c) Write an example of the local unit that measures mass.
Answer: An example of the local unit that measures mass is Mana/ Pathi/ Muri/ Dharni.
d) Define time.
Answer: The period or duration between any two events is called time.
e) What is length?
Answer: The distance between any two points is called length.
f) Define thermometer.
Answer: A thermometer is a device which is used for measuring the temperature of an object.
g) What is energy?
Answer: The capacity or ability to do work is called energy.
h) Define SI Unit.
Answer: The unit of measurement which is accepted all over the world as a basic unit is called a Standard unit 'SI unit'.
Or,
The globally accepted measurement system as a basic unit is called SI unit 'The System International Units'.
i) What are the elements of scientific method?
Answer: The elements of scientific methods are -
i) Observation
ii) Question
iii) Research
iv) Hypothesis
v) Experiment
vi) Analysis
vii) Result
viii) Conclusion.
5. Long answer questions.
a) Enlist the steps of scientific learning process.
Answer: The scientific method is just a process that scientists use to verify new facts. The list of steps for scientific learning process are as follows:
i) Observe and study the events or objects around us (Make an observation),
ii) Devise questions about the event or object (Ask question),
iii) Predict the most likely answer to the question (Do background research),
iv) Form a hypothesis.
v) Text your predictions with experiments (Conduct experiment),
vi) Record the findings of the experiment (Report your Results),
vii) Present the conclusions in a report (Result),
viii) Extract conclusions based on the findings (Extract conclusions).
b) What improvements were made in measuring system with the introduction of standard units?
Answer: With the introduction of standard units in measuring system, the measurement of any object is more accurate, consistent, reliable and globally accepted.
c) What are the applications of measurement?
Answer: The applications of measurement are -
1. It is useful for selling and buying goods.
2. It is essential for making and preparing food.
3. It is important for conducting scientific experiments.
4. It is important for global understanding of the quantity of substances.
5. It is useful to measure raw materials in industries, etc.
#What are the importance of measurement?
d) What problems might we face if measuring systems were not established?
Answer: We might face the following problems if measuring systems were not established-
i) Unable to conduct scientific experiments,
ii) Unable to prepare tasty food without knowing the accurate amount of ingredients added to it,
iii) Unable to stitch clothes without knowing the accurate size of our body,
iv) Difficult to buy and sell things such as vegetables, sugar, oil, pulses, rice, wheat flour, etc.,
v) Most importantly the lives of people got worst.
e) Your father brought you a pair of shoes. When you wore the shoes, you realized there was a problem. The shows were too long. Why might such a problem arise and how can it be mitigated?
Answer: Such problem arise because the accurate measurement of the size (length) of the foot was not taken by your father. It can be mitigated by taking the accurate measurement of the foot.
g) There would be no water supply tomorrow at home. How much water should be stored for tomorrow? Why do you emphasize on estimation then?
Answer: We use 500 litres of water daily. So, 500 litres of water should be stored for tomorrow.
We emphasize on estimation of water for tomorrow to store water for drinking purpose and to perform various activities.
h) Take two eggs and put one in a plastic or ceramic bowel containing vinegar or lemon juice and another in a bowel containing cold water for 3-4 days? After that, compare both eggs and find what changes are seen in both eggs? Draw a conclusions from your findings. Explain the work you did according to the steps from the scientific learning process.
Answer: The explanation of work that we perform according to the steps of scientific learning process is listed below:
i) Observe and study the events or objects.
Here, vinegar or lemon juice are acids. Eggshells are made of calcium carbonate. If we put an egg in a plastic or ceramic bowel containing vinegar or lemon juice, the eggshell will absorb the acid and dissolves i.e. eggshell will disappear and egg becomes bigger.
Also, If we put an egg in a bowel containing cold water for 3-4 days, the cold water help in keeping egg whites from getting rubbery.
ii) Ask questions.
- Do the vinegar or lemon juice break down the eggshell?
- Does an egg kept inside vinegar and lemon juice become bigger in size?
- Does an egg kept inside vinegar and lemon juice totally break?
- What happens to the egg that was kept inside the cold water?
- Does an egg kept inside cold water break?
6. Write differences between:
a) Local unit and Standard unit.
Answer: The differences between Local Unit and Standard Unit are given below:
| Local Unit | Standard Unit |
|---|---|
| 1. It is used in local or regional areas. | 1. It is used internationally/globally. |
| 2. It is not-standard and less accurate. | 2. It is consistent throughout measurements. |
| 3. It is not suitable for scientific measurements. | 3. It is accurate, reliable, widely accepted and suitable for scientific measurements. |
b) Area and Volume
Answer: The differences between Area and Volume are given below;
| Area | Volume |
|---|---|
| 1. The space covered by a surface of an object is called area. | 1. The space occupied by an object is called volume. |
| 2. SI unit of area is square metre (m²). | 2. SI unit of volume is cubic metre (m³) or litre (l). |
7. Give reasons (Explain).
a) The local units are not internationally accepted for measurement.
Answer: The local units are not internationally accepted for measurement because they differ from person to person and from one place to another place and it is not accurate.
#Why local units are not internationally accepted for measurement?
b) SI units are used for scientific measurement.
Answer: SI units are used for the scientific measurement to avoid confusion when measuring among the scientists all over the world.
Or,
SI unit is used in most places around the world, so our use of it allows scientist from desperate regions to use a single standard unit in communicating scientific data without vocabulary confusion.
Or,
SI units are used for scientific measurement because it is accurate and accepted all over the world.
#Why SI units are used for scientific measurement?
c) We need standard units to measure physical quantities.
Answer: We need standard units to measure the physical quantity because it helps to maintain uniformity about measurement throughout the world.
Or,
We need standard units to measure physical quantities because it is accurate and accepted all over the world.
#Why we need standard units to measure physical quantities?
d) Kilometre is the multiple of metre.
Answer: Kilometre is the multiple of metre because it is larger unit than metre.
#Why kilometre is the multiple of metre?
8. Diagrammatic questions.
Identify the given diagram and write the physical quantity which they measure.
i) Watch - Watch is used to measure the time.
ii) Tape - Tape is used to measure the length of an object.
iii) Digital thermometer - Digital thermometer is used to measure the body temperature.
iv) Measuring cylinder - Measuring cylinder is used to measure liquids.
NUMERICAL PROBLEMS
9. Convert the following as mentioned:
a) 2 hours to second
Solution:
Here,
= 2 hours
= 2 × 60 minutes [∵ The relation between Hour and Minute is 60] [hour 60 minute 60 second] [Important: To convert larger unit to a smaller unit - MULTIPLY (×)]
= 120 minutes
= 120 × 60 seconds [∵ The relation between Minute and Second is 60] [hour 60 minute 60 second] [Important: To convert larger unit to a smaller unit - MULTIPLY (×)]
= 7200 seconds. Ans.
Or,
Here,
= 2 hours
= 2 × 60 × 60 seconds [∵ The relation between Hour and Minute is 60. Also the relation between Minute and Second too is 60] [hour 60 minute 60 second] [Important: To convert larger unit to a smaller unit - MULTIPLY (×)]
= 7200 seconds. Ans.
b) 3 m 55 cm to cm
Solution:
Here,
= 3 m 55 cm
= 3 × 100 cm + 55 cm [∵ The relation between metre and centimetre is 100] [m 10 dm 10 cm 10 mm] [Important: To convert larger unit to a smaller unit - MULTIPLY (×)]
= 300 cm + 55 cm
= 355 cm. Ans.
c) 736 cm to m
Solution:
Here,
= 736 cm
= (736 ÷ 100) m [∵ The relation between centimetre and metre is 100] [mm 10 cm 10 dm 10 m] [Important: To convert a smaller unit to a larger unit - DIVIDE (÷)]
= 7.36 m Ans.
d) 15 kg to gram
Solution:
Here,
= 15 kg
= 15 × 1000 gram [∵ The relation between kilogram and gram is 1000] [kg 10 hg 10 dag 10 g (gram)] [Important: To convert larger unit to a smaller unit - MULTIPLY (×)]
= 15,000 gram. Ans.
e) 2m² to cm²
Solution:
Here,
= 2m²
= 2 × m × m
= 2 × 100 cm × 100 cm [∵ The relation between metre and centimetre is 100] [m 10 dm 10 cm 10 mm] [Important: To convert larger unit to a smaller unit - MULTIPLY (×)]
= 20,000 cm². Ans.
f) 4m3 to cm³
Solution:
Here,
= 4m³
= 4 × m × m × m
= 4 × 100cm × 100cm × 100cm [∵ The relation between metre and centimetre is 100] [m 10 dm 10 cm 10 mm] [Important: To convert larger unit to a smaller unit - MULTIPLY (×)]
= 4,000,000 cm³. Ans.
g) 8 km to metre
Solution:
Here,
= 8 km
= 8 × 1000 m [∵ The relation between kilometre (km) and metre (m) is 100] [km 10 hm 10 dam 10 m] [Important: To convert larger unit to a smaller unit - MULTIPLY (×)]
= 8,000 m. Ans.
h) 23817 g to kg
Solution:
Here,
= 23817 g
= (23817 ÷ 1000) kg [∵ The relation between gram (g) and kilogram (kg) is 1000] [g 10 dag 10 hg 10 kg] [Important: To convert smaller unit to a larger unit - DIVIDE (÷)]
= 23.817 Ans.
i) 5 km 325 m into metre
Solution:
Here,
= 5 km 325 m
= 5 × 1000 m + 325 m [∵ The relation between kilometre (km) and metre (m) is 100] [km 10 hm 10 dam 10 m] [Important: To convert larger unit to a smaller unit - MULTIPLY (×)]
= 5,000 m + 325 m
= 5,325 m. Ans.
Extra Question and Answers:
A. Define a physical quantity. Write the SI units of mass, length and time.
Answer: The quantity which can be measured is called physical quantity. The SI units of mass is kilogram (kg), length is meter (m) and time is second (s).
#What do you mean by physical quantity?
B. Define measurement and the SI system of units.
Answer: Measurement is the process of comparing an unknown physical quantity with a standard known quantity.
The system of units recommended by the International Convention of Scientists held in France is known as the SI system of units. In SI system of units, mass is measured in kilogram (kg), length in meter (m), time in second (s) and temperature in Kelvin (k).
#What do you mean by measurement? What is SI system of units?
C. What is a standard unit?
Answer: The unit of measurement which is accepted all over the world as a basic unit is called a Standard unit.
D. Define mass and write it's units.
Answer: The amount of matter contained in a body is called mass. The units of mass are gram, kilogram, quintal and metric ton.
#What do you mean by mass?
E. Define CGS and FPS systems.
Answer: The system of units in which length is measured in centimeter (cm), mass in gram (g) and time in second (s) is called CGS system.
The system of units in which length is measured in foot (ft), mass in pound (lb) and time in second (s) is called FPS system.
#What is CGS System? #What is FPS system?
F. Write the full form of MKS and FPS.
Answer:
The full form of MKS is Metre, Kilogram and Second.
The full form of FPS is Foot, Pound and Second.
G. Write any two disadvantages of the use of local units.
Answer: The two disadvantages of the use of local units are:-
1. With local units such as haat or cubit, bitta, foot, etc in measuring length, it is not reliable and accurate because it varies/differs from person to person.
2. With local units such as mana, pathi, muri, dharni, pau, etc in measuring the mass of a substance, it is not reliable and accurate because it varies/differs from place to place.
H. Write the differences between M.K.S. and C.G.S . System.
Answer: The differences between M.K.S. and C.G.S. System are as follows;
| MKS System | CGS System |
|---|---|
| 1. In MKS System, the length is measured in metre, mass in kilogram and time in second. | 1. In CGS System, the length is measured in centimeter, mass in gram and time in second. |
| 2. MKS System is also called metric system. | 2. CGS System is known as the French System of units. |
| 3. In measuring force, MKS system using Newtons as the unit is widely accepted worldwide. | 3. In measuring force, CGS system using dyne as the unit is seldom used. |
| 4. In measuring volume of liquids and solids, the liter and the cubic meters are always used. | 4. In measuring volume of liquids and solids, the liter and the cubic centimeters are or cc is less used. |
| 5. The MKS System is more popular than CGS System. | 5. The CGS System is less popular. |
I. Write the differences between kilometre and kilogram.
Answer: The differences between kilometre and kilogram are as follows;
| Kilometre | Kilogram |
|---|---|
| 1. Kilometre is a unit to measure distance. | 1. Kilogram is a unit to measure weight and mass. |
| 2. The SI unit of length is kilometer (km). | 2. The SI unit of mass is kilogram (kg). |
Extra Numerical Problems:
A. How many metres (m) are there in 5 km 50 m?
Solution:
Here,
= 5 km 50 m
= (5 × 1000) m + 50 m
= 5000 m + 50 m
= 5050 m. Ans.
B. How many grams (g) are there in 5 kg 500 g?
Solution:
Here,
= 5 kg 500 g
= (5 × 1000) g + 500 g
= 5000 g + 50 g
= 5050 g. Ans.
C. How many seconds (s) are there in a solar day? Calculate the value.
Solution:
Here,
1 day
= 24 hours
= 24 × 60 minutes
= 24 × 60 × 60 seconds
= 86400 seconds (s)
Therefore, there are 86400 seconds (s) in 1 solar day.
D. If the length and breadth of a brick are 20 cm and 8 cm respectively, what is the area of the brick?
Solution:
Here,
Length of the brick (l) = 20 cm
Breadth of the brick (b) = 8 cm
Area (A) = ?
We know that,
Area of a rectangle brick (A) = l × b
= 20 cm × 8 cm
= 160 cm²
∴ Area of a brick = 160 cm²
Now,
The SI unit of area is m², we need to change cm² to m².
So,
A = 160 cm²
= 160 × cm × cm
= 160 × 1÷100 m × 1÷100 m [∵ The relation between centimetre and metre is 100] [mm 10 cm 10 dm 10 m] [Important: To convert a smaller unit to a larger unit - DIVIDE (÷)]
= 160 ÷ 10000 m² [160/10000 m²]
= 0.0160 m²
Therefore, the area of the brick is 0.0160 m². Ans.
Key Words
Procedure - an established or official way of doing something. (#procedure meaning in nepali language is प्रक्रिया, कार्यविधि)
Experiment - a scientific procedure undertaken to make a discovery, test a hypothesis, or demonstrate a known fact. (#experiment meaning in nepali language is परिक्षण)
Imagination - the faculty or action of forming new ideas, or images or concepts of external objects not present to the senses. (#imagination meaning in nepali language is कल्पना, कल्पन शक्ति भएको)
Phenomena - a fact, occurrence, or circumstance observed or observable. (#phenomena meaning in nepali language is घटना - plural of phenomenon)
Explore - travel through (an unfamiliar area) in order to learn about it. (#explore meaning in nepali language is अन्वेषण, खोज गर्नु)
Quantity - the amount or number of a material or abstract thing not usually estimated by spatial measurement. (#quantity meaning in nepali language is मात्रा, परिणाम)
Buoyancy - upthrust; an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. (#buoyancy meaning in nepali language is उछाल)
Prediction - a thing predicted; a forecast. (#prediction meaning in nepali language is भविष्यकथन, भविष्यवाणी)
Rational - based on or in accordance with reason or logic. (#rational meaning in nepali language is तर्कसंगत, निरूपण, सोच्न सक्ने)
Alkaline - Having the properties of an alkali, or containing alkali; having a pH greater than 7. (#alkaline meaning in nepali language is क्षारविशिष्ट, क्षारीय, विस्तृति, खायुगु)
Hypothesis - a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation. (#hypothesis meaning in nepali language is परिकल्पना, प्रमेय, उपकल्पना)
Energy - the strength and vitality required for sustained physical or mental activity. (#energy meaning in nepali language is ऊर्जा, हब्बा, शक्ति, ज्या यायेगु शक्ति, तागत)
Falsifiable - able to be proved to be false. (#falsifiable meaning in nepali language is मिथ्याकरण)
Analyze - examine (something) methodically and in detail, typically in order to explain and interpret it. (#analyze meaning in nepali language is विश्लेषण गर्नु)
Observation - the action or process of closely observing or monitoring something or someone. (#observation meaning in nepali language is अवलोकन, ठहर)
Community - a group of people living in the same place or having a particular characteristic in common. (#community meaning in nepali language is समुदाय, सामुदायिक, जाति)
Standard - a level of quality or attainment. (standard meaning in nepali language is स्तर, मानक, हैसियद)
Dice - a small cube with each side having a different number of spots on it, ranging from one to six, thrown and used in gambling and other games involving chance. (#dice meaning in nepali language is पासा)
Measurement - the action of measuring something. (#measurement meaning in nepali language is नाप, मापन)
Physical - relating to the body as opposed to the mind. (#physical meaning in nepali language is भौतिक, शारीरिक)
Fundamental - forming a necessary base or core; of central importance. (#fundamental meaning in nepali language is आधारभूत, मौलिक)
Estimation - a rough calculation of the value, number, quantity, or extent of something. (#estimation meaning in nepali language is अनुमान, आकलन गर्नु)
Uniformity - the quality or fact of being the same, or of not changing or being different in any way. (#uniformity meaning in nepali language is एकरूपता, एकनास)
Thermometer - a device used for measuring temperature, especially of the air or in a person's body. (#thermometer meaning in nepali language is ताप नाप्ने, थर्मोमिटर, ज्वरो नाप्ने उपकरण)
Recommend - put forward (someone or something) with approval as being suitable for a particular purpose or role. (#recommend meaning in nepali language is सिफरिस गर्नु, सल्लाह दिनु)
Traditionally - as part of a long-established custom, practice, or belief; typically. (#traditionally meaning in nepali language is परम्परागत)
Portable - able to be easily carried or moved, especially because being of a lighter and smaller version than usual. (#portable meaning in nepali language is सजिलै लैजान सकिने, पोर्टेबल)
Precisely - in exact terms; without vagueness. (#precisely meaning in nepali language is ठ्याक्कै, ठीक)
Duration - the time during which something continues. (#duration meaning in nepali language is अवधि, मात्र)
Temperature - A measure of the quantity of heat in an object, usually as measured on a thermometer.(#temperature meaning in nepali language is ताप, तापमान, तापक्रम)
Mitigate - make (something bad) less severe, serious, or painful. (#mitigate meaning in nepali language is कम गर्न)
Scientific - relating to science, or using the organized methods of science. (#scientific meaning in nepali language is वैज्ञानिक)
Local - relating to a particular space or place or serving only a small portion of something. (#local meaning in nepali language is स्थानीय)
Conclusion - the end or finish of an event, process, or text. (#conclusion meaning in nepali language is निष्कर्ष, अन्त, समाप्त गर्नु, निष्कर्षमा पुग्नु)
Length - the distance from one end of something to the other end. (#length meaning in nepali language is लम्बाइ)
Time - the duration between two events; the duration in which all things happen, or a precise instant that something happens. (#time meaning in nepali language is समय, ई, बेला, बखत)
Area - a particular part of a place, piece of land, or country. (#area meaning in nepali language is ठाउ, क्षेत्र, इलाका)
Volume - the space occupied by an object. (#volume meaning in nepali language is आयतन, मात्रा)
Analysis - detailed examination of the elements or structure of something. (#analysis meaning in nepali language is विश्लेषण, विभाग, पदच्छेद, अन्वय, व्यवच्छेद, विभेद)
Process - a series of actions or steps taken in order to achieve a particular end. (#process meaning in nepali language is विधि, प्रक्रिया, प्रणाली)
Inferring - to form an opinion or guess that something is true because of the information that you have. (#inferring meaning in nepali language is निष्कर्ष गरिएको, अनुमानित गरिएको)
Communication - the act of transferring information from one place or person to another. (#communication meaning in nepali language is सञ्चार, सूचना)
Stability - the state of being stable. (#stability meaning in nepali language is स्थिरता, स्थायित्व)
Conduct - do something in an organized way; take someone somewhere. (#conduct meaning in nepali language is सञ्चालन)
Tola, Pau, Dharni - local units of measurement of mass (#tola #pau #dharni meaning in nepali language are तोला, पाउ, धार्नि)
Calibration - the process of making the scale of a measuring instrument (#calibration meaning in nepali language is मापन, क्यालिब्रेसनद्वारा, अंशांकन)
Consecutive - in succession (#consecutive meaning in nepali language is लगातार, निरन्तर)
Milli - 1/1000 part of anything (मिली)
Centi - 1/100 part of anything (सेन्टी)
Deci - 1/10 part of anything (डेसी)
Deca - ten times bigger (डेका)
Hecto - hundred times bigger (हेक्टो)
Kilo - thousand times bigger (किलो)
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