00:00 Hello, my name is Tijani Musa Alad-Bukho, I'm your Physiist teacher.

00:19 The topic before us today is fundamental and derived quantities.

00:26 At the end of the lesson, students should be able to differentiate between fundamental

00:33 quantities and derived quantities.

00:37 Introduction.

00:38 I know majority of you present are not familiar with the topic because it happens to be one

00:45 of the first topics in the syllabus "Physis".

00:49 When we talk about "Physis", what do we mean by "Physis"?

00:52 We talk about the story of natural phenomena, which has to be with an event or fact that

01:00 is hard to explain sometimes.

01:04 But everything around us, everything we can see, everything that happens to us is what

01:10 the story of "Physis" is all about.

01:13 But "Physis" do not accept fact, law, theory, without experimentation.

01:19 And that is why "Esperementation" is a core aspect of "Physis" and other physical

01:25 sciences.

01:26 Theories and other hypotheses are verified and established as scientific truths by

01:34 means of experiments conducted.

01:36 So measurements, which is the major, which is the core of today's topic, is an integral

01:42 part of experiments.

01:43 We are the magnitude and the relationship among different physical quantities are used

01:50 to verify the truth or the theory of hypothesis.

01:55 So meaning that in order for a scientist to establish a relationship, in order for a scientist

02:03 to come up with a theory, most of the well-known theory that anything that goes up comes down,

02:08 the first of all initially takes some measurements, in order for them to be able to achieve this.

02:14 So physical quantities are no meaning, unless it's measured, it's measured, quantified,

02:22 and give a unit.

02:23 Therefore, we need a number or quantity and unit of measurement to specify physical quantity

02:30 in "Physis".

02:34 When we talk about physical quantity, we are talking about quantity that can be, that

02:41 a numerical value can be attached to.

02:44 And in the realm of "Physis", there are two types of physical quantity, which include

02:51 the fundamental quantity and the derived quantity.

02:56 As the name implies, the fundamental quantity is just like the foundational quantity, the

03:03 base quantity.

03:04 So every other quantity can be derived from the fundamental quantity.

03:09 And to the second one, which is the life quantity, it means there are subsets of the

03:14 derived quantity, and every other thing from this can be, can be, is elementary to this

03:21 meaning, it can be derived from the fundamental quantity.

03:25 So fundamental quantity, instead of quantity, instead of fundamental quantity, are

03:30 divining every unit system, meaning every fundamental quantity as your unit, and the corresponding

03:38 physical quantity are called the fundamental quantity.

03:42 Fundamental units are independently divined, and often, the quantity are directly measurable

03:49 in physical system.

03:52 Fundamental quantity are the base quantity of a unit system, and they are divining independently

03:57 of the other quantity.

03:59 The table below shows the fundamental quantity.

04:03 There are seven in number, and as I've said earlier, every other quantity are derived from

04:09 the fundamental quantity.

04:12 Let's go to the next slide to see the fundamental quantity.

04:16 So we have the fundamental quantity, the fundamental units, and the symbol.

04:21 The first one is length, which is a major distance, and it is normally measured in meter, the unit

04:29 is meter.

04:30 Why the symbol is represented with a capital M?

04:34 The mass of an object, which is a major, which is a function of the quantity of matter

04:40 in a body, is usually measured in words in kilogram.

04:44 Sometimes can be measured in gram, but the standard unit is the kilogram, which is KG

04:50 as symbol, the time, which is a function of everything, is measuring second, and the symbol

04:58 is what is of X.

05:00 The temperature of an object has about three different units.

05:07 Temperature can be measured in cell shields, it can be measured in Kelvin, and it can

05:12 be measured in far-right.

05:14 Now the standard dies unit for temperature is what is Kelvin, and it is usually denoted

05:20 with capital letter K.

05:22 Electric currents, which is the rate of flow of charge during the second, circuits, is

05:28 measured in ampere, and it is always symbol, it is always symbolized with capital letter

05:34 A.

05:35 A amount of substance is a very powerful concept in the realm of physics, in the realm of chemistry.

05:42 It could mean the mass of the substance over the molar mass, and it can be, it has another

05:50 set of relationship, too.

05:52 It can mean the concentration of the substance times the volume over the 1,000, but in physics

05:59 we take it to be more, and the symbol is always MOL.

06:04 And the last one is luminance intensity, the word luminance means light, and intensity is

06:10 talking about the brightness, how great it is.

06:13 So it is always major in candela, and the symbol is CD.

06:20 The life quantity, the era in a Zostibu number of the life quantity.

06:27 For the scope of this study, we will be limited to some importance, the life quantity.

06:34 What I'm saying in essence is that there is no textbook in the world that will cover all

06:40 the derived quantity.

06:43 But for better understanding, we will look at the most important of all the life quantity.

06:48 So what is the life quantity?

06:50 The life quantities are based on, they are based on fundamental quantity, and they can be

06:57 given in terms of fundamental quantity.

06:59 There are countless number of derived quantity, and the table shows the life quantity and their

07:06 units.

07:07 So this table doesn't show completely the number of the life quantity and their units,

07:13 so we only is limited.

07:16 As I said, there are numerals, there are in a Zostibu number of these derived quantity.

07:22 So the first one which happens to be the area, anything area has to be a major of the length

07:30 and the breadth.

07:32 And since length is major in meter, the breadth as well is major in meter.

07:36 So the problem of the two gives the meter square.

07:39 So the unit of area is always meter square.

07:43 The volume, volume is a three-dimensional object, and as such, there is always the length,

07:51 the breadth, and the height.

07:53 So when you, the product of the three dimensions, we give all the words the meter cube.

08:00 So we have density.

08:02 Density is dependent on the mass and the volume of an object.

08:07 If you want to know how dense an object is, an object is, the first thing you consider is

08:13 the mass of that particular object.

08:15 So the more the mass of an object, the more the density.

08:18 So meaning there is a positive relationship between the density of an object and the mass.

08:24 So the mass of an object, as said, which is also a fundamental quantity, is always major

08:30 and worth in kilogram, and volume, which is this, is major and worth in meter, in meter

08:36 cube.

08:37 So because we are having divided, divided in physics or in mathematics means path, we use

08:43 minus, to represent it meaning kilogram, meter cube, per meter cube.

08:50 The velocity of an object is displacements over the time.

08:56 So displacement is major and meter, and the time is major and worth in seconds.

09:01 So aggregately, this is called meter per seconds, but I need to quickly make something clear

09:07 now because people do misconstrue the speed with the velocity.

09:13 We need to know that speed is distance over time and that makes it a scalar quantity.

09:21 Why the velocity is displacement over time and as such, it is a vector quantity.

09:28 We have the acceleration, acceleration is usually changing velocity over time taking and

09:34 the unit is meter per second squared.

09:38 The weight of an object is the total of the mass and the acceleration due to gravity.

09:45 And this can be, the mass is always major in kilogram, on a normal day, the mass is always

09:53 major in kilogram, why the acceleration due to gravity is major in meter per second squared.

10:03 So it is pertinent at this point in time to know that kilogram meter per second squared

10:10 is equivalent to new thing.

10:13 So seeing this, just like new thing, might not be too clear to students.

10:17 So this is major in kilogram and this is meter per second squared.

10:21 So more meter per second squared is equivalent to new thing because we surely discussed this

10:28 in this subsequent class.

10:30 At the same time, this new thing was given in honor of the great scientists called Isaac

10:36 Newton.

10:37 The next one is momentum, momentum is the plural of mass and velocity.

10:42 The mass as well is major in kilogram and velocity is major in meter per second squared.

10:51 So the equivalent of this kilogram meter per second squared is new thing second.

10:57 So it is even another derivative and the other derivative is kilogram meter per second squared

11:04 should you come across it in another textbook for further research.

11:09 Pleasure.

11:10 Pleasure is given as force per unit area.

11:14 So the force of an object over the area, don't forget that the force is the same thing as

11:19 weight.

11:20 They have the same unit.

11:21 So the unit of force is new thing and the unit of area is meter per second squared.

11:29 So one new thing meter, no one new thing per meter squared is equivalent to Pascal.

11:37 This is Pascal or new thing per meter squared.

11:39 So is having another unit which can be millimeter mercury, which can be bar and some other units.

11:49 The energy or work done, they have the same unit.

11:53 So energy or work done is force times distance and force is major in Newton, why distance is

12:00 major in words in meter.

12:03 So it's having an equivalent.

12:05 Sometimes if you don't see it as new thing meter, it is usually within us jou.

12:11 So meaning that one new thing meter is equivalent to jou.

12:16 And the last one on the list is power, power is the rate of change of work per time taking.

12:24 So work is major in jou and the time is major in words in seconds.

12:30 So the unit of power could be jou per seconds or watts.

12:39 So these are the common ones that you always find in the study of our physics, but there

12:46 are other ones in the area of heat, electro dynamics, AC circuits, wave, light and light.

12:57 In SI units, derived units are often given name of people such as Newton.

13:02 I mentioned this earlier and jou.

13:06 In the fundamental quantity, we have three most important ones.

13:12 And these three most important ones include the length, the mass and time.

13:19 And don't forget that the length is major in meter, why the mass is major in kilogram and

13:26 the time is major in second.

13:30 So measurement of time, of mass, we are most often time, we are very much interested in

13:40 knowing the mass of an object.

13:43 So what are the instruments that we use for measuring the mass of an object?

13:48 There are about four, five, six of them, but this course, we look about, we consider,

13:56 about four or five of them.

13:58 So the first one is not strange to some of us.

14:01 We commonly use the time, though, yeah, let me clarify something.

14:06 People do mix it up, they use it interchangeably, weight and mass.

14:11 I've had it time without non-biased students, we say, I want to measure my weight.

14:17 You can never measure your weight.

14:20 What you measure is the mass.

14:23 Because weight is a function of mass and acceleration due to gravity.

14:27 So if you want to measure the mass of an object, which means the quantity of mater in a body

14:34 and is a function of density.

14:36 So you see different objects with different masses.

14:40 And mass is talking about the evidence of an object.

14:44 So in any case, the units are based on item purchased.

14:49 For example, we buy gold in gram or milligram.

14:53 That's in milligram, provisioning gram and kilogram and express cargo in tons.

14:59 So in large quantity, we have tons.

15:02 You understand, we can have bag of cement, more than 50 kg.

15:07 So in that case, we measure it in tons.

15:10 So we can use some of these measuring devices to do that.

15:14 But if we are measuring very small objects, we can still use some more instruments.

15:20 This is an instrument that majority of us are familiar with.

15:24 For those of us that we use to buy fish, raw fish, turkey and the rest of them, we see

15:29 this in a food shop.

15:33 So we can use same instrument for measuring the above listed item.

15:38 Different measuring devices have to be used for item of smaller and larger masses.

15:45 In this section, we will study about some of the instruments used for measuring masses.

15:50 So the first one is common beam balance.

15:54 So the common beam balance actually is as a measure.

16:00 It's as a standard reference measure from 5 grams to 5 kilogram.

16:06 And when we try to compare the mass of objects of 5 grams, that is so small compared to 5 kilogram.

16:14 So if we want to measure any object within this range, within the range of 5 grams to 5 kilogram,

16:21 we use the common beam balance and it's measured it accurately.

16:27 The next one is the two plan balance.

16:31 And that is the diagram on the board.

16:35 This type of balance is commonly used in provision and grocery shop.

16:39 That's the figure 12.

16:42 The balance is compared sample mass with standard reference mass.

16:46 The balance was on top of the beam and can conveniently place on the table top.

16:53 This balance can measure mass accurately to 5 grams.

16:57 So meaning most of the time, we use this to measure object that is not as heavy as that.

17:05 So object is as heavy as 5 grams, which is not that heavy, so this type of measuring device

17:14 can be used for measuring it.

17:17 The next one is the physical balance and it can be shown on the board in most of our lab.

17:23 We see this kind of instrument there.

17:26 And this is used in the lab and is similar to the beam balance.

17:31 Because it is a lot more sensitive and can measure mass of an object correct to milligram.

17:39 Meaning, because milligram is a subset of gram, milligram is smaller to gram.

17:46 Why, in comparison with them, when you try to just oppose, gram is too very much smaller

17:53 to kilogram.

17:54 So when we are measuring a very small, an object with a very small size, size of a 10

18:01 milligram, 20 milligram, which you can see is just like the size of the drug you understand

18:06 that we take.

18:07 So object of this size, the object that we can use to measure it accurately is the physical

18:13 balance.

18:14 And this is normally used in pharmaceutical and the most times in the lab.

18:19 The digital balance, this is the most accurate and commonly used balance in the contemporary

18:28 world because it's measured accurately with little or no error.

18:35 So it can be used to measure objects of any length, even as small as few milligrams.

18:43 You know, we measure as small as, let's pick a value as small as 10 milligram and above.

18:49 So this digital balance can be used to do that and it's measured accurately.

18:56 Spring balance.

18:59 This is also one of the majoring device, but it does not measure the mass directly.

19:05 It's measures the weight of an object.

19:08 So this balance helps to find the weight of an object.

19:11 It's consists of a spring, this is the spring.

19:16 Spring fixed at one end and shook and shook attached to the rod.

19:21 This is the hook attached to the rod at the right.

19:24 So it works on the principle of Hook's law.

19:27 The Hook's law is a law that was stated by one of the greatest scientists, Robert Hooks.

19:35 And it states that the force applied is directly proportional to extension.

19:41 Meaning that the more the force applied to the end of this spring, the more the extension.

19:49 And it's normal.

19:50 It's just like when you just get a new boxer.

19:54 You know, when you keep putting on the boxer on daily basis, you started noticing an extension

20:00 in the boxer too many.

20:03 You apply a force directly or indirectly on the boxer which brings about the expansion.

20:08 So that is what Hook's law is saying.

20:10 Explain that additional weight produced a proportional increase in the length of spring.

20:17 So meaning the more the force applied to an object, the more the extension.

20:24 The difference between mass and weight of an object.

20:28 So I need to clarify this more and more at this point in time.

20:32 When we talk about mass, we are talking about the quantity of matter contained in a body.

20:39 The quantity of matter contained in a body.

20:44 And the mass of an object is always major in kilogram.

20:48 But when we talk about weights, weight is the normal force meaning the force exited on

20:53 the surface of the body against the gravitational pull.

20:59 So as a result of that, the weight of an object is always given as the poorer of mass and

21:06 the acceleration due to gravity and the flow.

21:11 The gravitational force acting on an object is given mathematically as this.

21:17 This is the mass times the weight, the acceleration due to gravity.

21:22 And the mass is always major in kilogram as said earlier why the g, which is the acceleration

21:27 due to gravity, is having an equivalent unit with the normal acceleration.

21:33 And that is a meter per second squared.

21:37 So the acceleration due to gravity is something that tends to bring an object down.

21:42 And the normal day, if this is true and upward, momentarily when it gets to a point that

21:49 is the maximum velocity into the zero, the final velocity would be zero before coming down.

21:54 So what tends to bring it down is the acceleration due to gravity.

22:00 For example, if a man has a mass 50 kg on the head, then what is his weight?

22:06 As established mathematically, the weight of an object is the poorer of mass and the acceleration

22:13 due to gravity.

22:14 That is, mass m, mass m times g, which is the acceleration due to gravity.

22:20 And that is the formula on the board.

22:22 The mass of the man is 50 kg, his weight will be 50 times 9.8, although in some test book

22:31 you will see this acceleration due to gravity to be 10 meter per second squared, but numerically

22:38 the actual value of acceleration due to gravity is 9.8.

22:43 And as such, I'm using it in this course of study as 9.8.

22:47 So should you eventually come across it as 10, it can be given us 10 in some test book.

22:53 So multiplying 50, which is the mass of the man, times the acceleration due to gravity,

22:58 which is 9.8, we have 490.

23:03 And I showed you that weight or the force of an object is usually measured in new things.

23:08 So the unit is new thing or you write copy 2 letter n.

23:13 The difference between mass and weight of an object, the first one is we need to know that

23:21 mass is one of the most important fundamental quantity that we need to know why the weight

23:31 is a derived quantity because we derive it from the fundamental quantity.

23:37 The other one is mass as magnitude alone and when something has only magnitude that makes

23:44 its scalar quantity, but a weight as magnitude and the direction and hence its vector quantity.

23:53 The third one is it is the amount of matter contained in a body as explained earlier,

23:59 the amount of matter, which is the function of its density.

24:03 By the weight, it is the normal force exerted by the surface on the object against gravitational

24:11 tool.

24:13 The fourth one is the mass of an object, irrespective of where you are taking it to.

24:20 The mass of an object we always remain constant.

24:24 It is the same in Android, it is the same in London, it is the same everywhere.

24:29 Because the weight of an object varies from place to place, most especially at the pull,

24:36 at the pull of the x in the equator, the weight of an object varies.

24:41 So the fifth one is that it is major using physical balance and the weight of an object it is

24:49 major using is spring balance.

24:52 So one important thing we need to know before taking the last one is since this is major

24:57 using the physical balance, it works on the principle of movement, that is under equilibrium

25:04 of forces, meaning the forces on the clockwise direction must always be equal to the forces

25:11 on the anticlockwise direction and for weight, it works on the principle of uxlo, which states

25:19 that the force is proportional to extension, meaning the more the force, the more the extension.

25:24 So the last one is in terms of units, the unit of mass is kilogram and that of weight is

25:32 newton.

25:35 Evaluation, divine, fundamental and the life quantity in your own language to the best

25:43 of your knowledge.

25:44 So explaining that way, second, list the seven fundamental quantities and their units.

25:52 The third question, if a man has a mass of 30 kg, find his weight, taking G to be 10 meter

26:02 per second squared.

26:04 Number four, state the unit of the following derived quantity.

26:08 Number one, impulse, the second one, young modulus, the third one, magnetic flux density

26:16 and the fifth one resistance of the resistor and the last one, which is capacitance of capacitor.

26:26 Thank you for watching.

26:28 My name is Tijani Musa, Ola de Krupo.

26:33 See you next time.