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If you are a student of engineering, you will learn about MLT and FLT system among the units. I majored in mechanical engineering and have learned about these concepts in fluid dynamics. In this post I would like to briefly explain it.
It is actually a concept that emerges from exam questions and many employment exams. I think it is one of the problems that the percentage of correct answers is not so high even though it is an easy idea. The reason for this is probably that you are unfamiliar with the SI unit system (International System of Units) prior to conversion to the MLT / FLT system.
So we will look at the SI units of various physical quantities and let you know about the MLT and FLT systems after that. I will try to solve the problem by bringing three problems below. I will try to solve mainly MLT system.
First of all, it is the turn of this article.
1. SI units of several physical quantities
2. MLT, FLT brief description
3. Description of three problem solving
1. SI units of several physical quantities
The SI unit, which is an international unit, has 7 basic units and a derived unit. I will not distinguish between them and I have listed the major physical quantities.
- Length: meters (m)
- Mass: kg (kg)
- Time: sec (s)
- current: ampere (A)
- Temperature: Kelvin (K)
- molar mass: mol (mol)
- Brightness: Candela (cd)
- Angle: Radian (rad)
- Frequency: Hertz (Hz)
- Power: Newton (N)
- Pressure: Pascal (Pa)
- Energy: Line (J)
- Uniformity: Watt (W)
- Charge amount: Coulomb (C)
The amount of the physical quantity mentioned above must be memorized. It is because these tests are not given in the tests that actually give grades. And, as you can see from the problem below, it does not tell you about the problem.
2. MLT, FLT brief description
- Two types of Dimension system
① M.L.T dimension system: mass [M], length [L], time [T]
② F.L.T Dimension: force [F], length [L], time [T]
[F] = [MLT ^ -2] since F is [N], m is [M] and a is [m / s ^2]
3. Description of three problem solving
- This is a problem that has been addressed to general machine engineers, public corporations and public officials.
[Problem 1] Which MLT dimension is displayed incorrectly?
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| 가) Pressure, 나) Work, 다) Power, 라) Kinematic number |
[Problem 1 explanation]
As I said above, I'm not asking for a unit in the question, but I'm asking. All of the above SI units must be memorized. So let's solve the problem. Please read the following slowly, because I have solved it in the following order.
That is, the answer is 가). The MLT dimensional system of pressure is exactly as it came from the upper pool.
Assuming that the unit is memorized by default, the problem solving process was carried out. It seems to be understandable if you look slowly in order 가, 나, 다, 라. However, the unit of the kinematic number is Stokes = cm ^ 2 / s in the last 라).
However, the prefix, centimeter (c)
[Problem 2] What is the dimension of the viscosity coefficient?
[Problem 2 explanation]
First, the basic unit of viscosity is Poise. Poise is the basic unit of viscosity and can be expressed as Poise = Pa * s = N / m ^ 2 * s. In other words, it can be interpreted as.
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| viscosity coefficient |
[Problem 3] What is the correct dimension of energy?
[Problem 3 explanation]
The dimension of energy is also mentioned in SI unit 1 above, but the unit of energy is line (J).
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| dimension of energy |
More than! SI unit, MLT, and FLT dimension system, we briefly explained the problem, and I tried to solve the problem with the issue. I hope this helps you. If you have any questions, please log in with your Google ID and leave a comment below.