[ÔN TẬP GIỮA KÌ 1] BUỔI SỐ 03 - THẦY VNA

Hello, everyone. My name is Dang Duong, Kim Yen, Nhat Minh, Trung Kien, Anh Phu, Quoc Nguyen. I lost the announcement, Dang Duong. You guys left the announcement button. The announcement is how to make your voice straight. I just finished A1 class. So my voice is a bit hoarse. I spent 15 minutes in A1 class. 30 questions in a row. I almost died. I went to school early today. I was late for a few days. I was late so I slept late. I woke up late in the morning. I had a lot of appointments. So I woke up a bit earlier. I woke up at 9.30am. This is probably the last day of the week. I will be busy on Friday. On Friday, you guys can see me in the group chat. On Saturday, I don't have the energy to live stream. Because on Saturday, I have to go to class in the afternoon. I'm tired. I want to take a break on Saturday. Because on Sunday, I have to wake up at 2am. So I'm tired. I don't think I will have any meetings this week. How is the mic? Is it normal? How is the mic? The mic is very normal. The mic. How is the mic? I can't turn on the fan. Is there a problem with the mic? The mic. The mic sounds bad. Still bad. It's still bad. It's less bad, bro. Hello. It's less bad, no? It's too bad. What's wrong with it? I just finished in class and it's still bad? Hello. It's so bad. It's like a bullet got in my head. Why is that? It's like a bullet. I don't understand why it sounds bad. My voice sounds so bad. Tomorrow I will change a new mic Tomorrow I will make a new mic The mic I usually use at home is a red one It's a Mixi mic It's about 4-5 million VND But the mic I'm using is a Tomas mic It's only 1 million VND The mic I usually use at home is a red one When I livestream It's about 5 million VND It's very clear It's great for singing karaoke But this mic I'm using is only 1 million VND This mic I can't see it It's only 1 million VND It has 3 legs Can you see it? Let's study Let's get to work You should test that mic someday I will sing that mic I will sing that 5 million VND mic Today's livestream is a bit early Many of you think that It's 10 o'clock, right? Today's livestream is a bit early To go home early and sleep early It takes one day to study early Today's topic is 30 sentences If you study today, it will take a day It's your first session Keep 30 sentences You must sleep early Coach Trung I will teach you You guys give him a name to share Because in this group, it's not like a fanpage The teacher is going to live outside the fanpage, but he likes to live in the group, so it's quiet So you guys share to help the teacher Because in this group it is not accessible, it is not distributed on Facebook but outside the fanpage Outside the fanpage, it is distributed more So I really need you to share to help the teacher The teacher is already in the group, so it's quiet Let's start studying Let's get to work Question 1 Choose the correct answer to distinguish between horizontal and vertical waves It is based on the direction of movement and the direction of transmission So our question 1, answer C is correct Vertical waves are transverse waves Horizontal waves, the parts of the movement are perpendicular to the direction So question 1 is C Next, question 2 When a object moves slowly, the frequency and function decrease over time What does the function transform into? The function transforms into thermal energy At this time, the force of friction is negative, which hinders the movement of the object So our question 2 is C Next, question 3 Remember that the function transforms into thermal energy Next, question 3 The condition for the phenomenon of interaction is that the two waves combine That is, the two waves have the same direction, the same frequency, and the force of friction does not change over time Then question B is the most complete Plus the addition of the element is the same direction But question B is the most complete So question 3 is B Share with the teacher You can't compare it to yesterday Yesterday was almost 500 people Next, question 4 A wave oscillates when it moves in parallel Maximum speed when balanced is wrong Maximum speed has a large magnitude when it is at the edge The force drawn back The action of the object has a large magnitude proportional to the square of the edge is wrong The force drawn back is F minus Kx Not proportional to the square of the edge Proportional to the square of the edge, it must be a function Next, question C The speed of the object has a large magnitude when the object is in a balanced position That's right, there's a lot of C When passing through the balance, the speed of the object is 4C The force drawn back to the large magnitude when the object is in parallel is also wrong 4 is C Question 5 A moving object from the edge to the balance is moving faster Going to balance is moving faster So our question 5 What is the correct answer? The answer is A Remember, in a parallel universe, there is no constant speed or constant speed Because the speed is constant, there is no constant change Next, question 6 The frequency of the wave is 1 over 2π times g over L So our question 6 What is the correct answer? The answer is B Next, question 7 The speed of the wave is 0.2 meters per second, which is 10 seconds The distance between the two points closest to each other is converted to each other On the same direction The closest to each other is λ divided by 2 What is λ? V times T divided by 2 0.2 times 10 is 2 2 divided by 2 is 1 The answer is B Question 7 is B Question 8 The distance between the two points closest to each other is converted to each other Question 8 is B There are many ways to talk about the wave The wave is the distance between the two points closest to each other There are many ways to talk about the wave Next, question 9 The speed of the wave decreases gradually through the environment The answer is B Question 10 The answer is C Next, question 11 A wave with a wavelength of 0.05m and a frequency of 2.5Hz What is the maximum speed of the object? The maximum speed of the object is omega squared times A Omega is 5π 5π squared times 0.05 What is the result? 12.3 meters per second The answer is C 11 is C Next, question 12 The answer is 1. What is the value of phi? 90 2. What is the value of phi? sin 4. What is the value of sin? 180 x3 The answer is 1 and 2 squares. 1 is 90, 1 is 180. Square. Square 1 and 3 are wrong. 1 and 3 must be mixed together. 2 and 3 must be square. 12 is A. Next, question 13. In the event of a wave interaction on the surface of the water, the distance between the two poles is continuous. On the line connecting the two waves, that is, on the straight line connecting the two sources, the two poles are continuously one and a half steps apart. On the straight line connecting the two sources, the two poles are continuously one and a half steps apart. So I ask you one more question like this, see if you remember or not. The distance between the two poles is continuous, but the word is mixed together. See? So what is the answer? Two poles are continuously mixed together. What is the answer? Do you remember? Yesterday, I just wrote a sentence like this. What is the word for question number 2? On the straight line AB, how many points are opposite poles? Right? Is that right? Right? That's right. To add the word mixed together, it must be one wave. Because here, we have a neutral pole, pole 1, pole 2. These are 3 poles in a row. Then 2 and 0 are 2 poles in a row and mixed together. Mixed together, it must be the same white or the same light. Do you remember this? See? Just a reminder. 13 is B. And if you add the word mixed together, it must be C. Question 14. That's right. The magnitude of the sound is L times the square root of I over I0. Right? And if it is 10 times the square root of I over I0, the unit must be decibel. So our question 14 must be B. Alright. Question 15. Wrong pronunciation. The process of transmitting is the process of transmitting. That's right. The process of transmitting the particle is wrong. The wave does not transmit the particle, it only transmits the state or the wave of the particle. Got it? It does not transmit the particle. Our question 15 is B. It only transmits the state, not the particle. So it's wrong. It transmits the wave, the state, and the energy. A, C, D are all correct. Next. Question 16. Wrong pronunciation when it comes to waves. The magnitude of the sound is the magnitude of the particle. That's right. Got it? The magnitude of the wave is the distance extended in phase continuously between two points. That's right. The word� talking closely the word closest. The wave transmits it in space. It's wrong. It doesn't have any reactant on it. Got it? It circulates in space. That's right. Got it? It circulates in space and changes properties in spacetime. Got it? C is correct. Next question 17. at a distance of 10cm This one is a potato, right? You can calculate the I, which is the magnitude of the sound I divided by P divided by 4πR Let's press it 0.225 is P 4πR is 0.1 Normal, right? You get the I is 1.79 Right? This is the watt divided by square meter The magnitude of the sound is L 10 log of I divided by I0 10 log of answer divided by 10 minus 12 I0 is 10 minus 12, right? So what is the result of this question? Oh, why is it 122? So where is it wrong? 4πR is P P is 1.79 Where is it wrong? Oh, why is it 122.52 dB? Oh oh oh oh oh oh oh oh Where is it wrong? Why is the comment wrong? Why do you guys have so much C? Oh, it's about 122.53 dB Those guys are stupid to choose C Oh my God Yeah! 122.53 Maybe it's wrong See? Maybe it's wrong It's wrong, it's wrong, it's wrong You guys still don't get it? Okay Learning with Mr. Dabane is very normal Question 18 What frequency can the human ear feel? The human ear can feel from 16 Hz to 20,000 Hz See? 40,000 Hz can't feel it 8 Hz can't feel it Only one of these two The frequency is 2 ms What is the frequency? 1 divided by 2 times 10 to the power of 3 This is 500 Hz 500 Hz is the ear Right? About this 18 is A, correct There is still a comment C The Japanese guy is studying The number is C Earth See? Shin is Shin Vinh Viet The Japanese guy Oh my God If you get this wrong It's a bit difficult It's a bit difficult to get this wrong See? It's easy to get it wrong It's a bit difficult to get it wrong See? Come on Question 19 The wave from A to M Along the wave The wavelength is 30 cm M divided by A is 15 cm 15 cm Lambda divided by 2 It's 180 degrees Right? 180 degrees It's the opposite of each other So question 19 is C If you are studying today It will be easier than yesterday See? It's harder than yesterday See? Question 20, 21 Let's go outside Here I just finished teaching the class My head is broken A class Look A class I can't show you It's a secret Come on Let's concentrate Question 20 and 21 It's easier than yesterday The wave from B to A over 2 It takes the shortest time 1 second People can tell The wave from A to A over 2 It takes T over 3 T over 3 is 1 second T divided by 3 seconds Right? The answer is C Of course, if you are not used to it If you are not used to it You have to use the circle Or you have to use the time In class, I often teach I don't use the time See? Look at this It's a little weak See? From the shortest wave from A to A over 2 It's here The shortest See? A over 2 This angle is 60 degrees This angle is 120 degrees 120 degrees is T over 3 T divided by 3 seconds See? Done Next Question 21 There is a spring hanging straight At an angle of 8 cm See? The time from the time of the magnetic field To the time of the magnetic field Is 1 over 3 seconds Our magnetic field Is in the ocean Right? Magnetic field I know it has 2 situations One is in the natural position If the spring has Spring Has a spring Or it's in the natural position If the spring is always straight See? So first The magnetic field is in the ocean This is the magnetic field And it only loses 1 over 3 seconds It means it has to go to the natural position Because it's in the natural position It means the spring It loses 1 over 3 1 over 2 seconds See? So this is the spring Has a spring and a straight Right? This is the natural position So minus delta L0 Loses 1 over 3 seconds Right? 1 over 3 seconds Is equal to 120 degrees So this angle is 60 degrees See? So delta L0 Divided by 2 Cos 60 is 1 over 2 So delta L0 is 4 cm See? Delta L0 is 4 cm So omega is 5 pi It's always straight Right? The speed of the object Is 2 cm away from the lowest position Away from the lowest position It means away from the ocean But pay attention The lowest position is the ocean 2 cm away from the ocean Is equal to 6 cm Because the ocean Is 8 cm away from the ocean So the lowest position is 2 cm Is equal to 6 cm The speed of the object Is done Apply the time independent formula V by omega The weight of A is minus X Right? 5 pi With the weight of 8 pi Minus 6 pi Just press the button See? The answer is