TRUST BLINDLY 🏻 110 MARKS GUARANTEED | RE-NEET 2026 | Yawar Manzoor sir

[00:00:00]This video is going to help you gain 90 to 100 marks, my dear NEET aspirants. Do not leave any of the topics which I am going to mention over here. I'll be showing the topics as well as the questions on those topics because these are the questions, these are the topics from which questions are expected, highly expected in your re-NEET 2026, my dear NEET aspirants. Let's dive into this and I will be discussing approximately 15 to 20 concepts in next 15 to 20 minutes. So, make sure you smash the like button and you share it with your friends, also. We have got first concept over here.

[00:00:35]That is distance and displacement in a circular path. Let's suppose this is a circular path. An object started traveling from A point to B point. Then this will be considered as distance and this will be considered as displacement.

[00:00:51]You will be directly remembering, "Sir, distance will be equals to R into theta." Theta is the angle how much it has cut. So, this is the radius R, this is the radius R, this is the angle theta.

[00:01:02]And my dear NEET aspirants, displacement will be 2R sin of theta by 2. That's it.

[00:01:09]Now, let's suppose an object has traveled from A point to B point. So, it has covered an angle of, I would say, 120°. So, distance in that case, displacement will be 2R sin of 120 by 2.

[00:01:21]Sin that is sin 60. Sin 60 is root 3 by 2. 2 and 2 will be canceled. So, displacement is root 3R. And if you find distance, distance will be R into theta and you'll be putting the value of theta over here and you are done. Then, my dear NEET aspirants, the concept two.

[00:01:36]This is the second concept. What is that? That is ratio of heights. So many times questions have been asked on the ratio of heights. Now, guys, see, if you release an object from certain height with initial velocity zero, acceleration constant, then, my dear NEET aspirants, after 1 second it will reach here, after 2 seconds here, after 3 seconds here, after 4 seconds here, and so on.

[00:02:00]If I say, "How much is the distance covered in 1 second?" You would say, "Sir, X. Consider it X."

[00:02:07]And if you find the value of this X by using this particular formula, so this X will come out to be that is 5. UT + 1/2 AT squared. You can check it over here.

[00:02:16]Directly remember X.

[00:02:18]Then, my dear NEET aspirants, how much is the displacement covered in 2 seconds? Sir, that would be 4X. Directly remember. Displacement covered in 3 seconds, 9X. Displacement covered in 4 seconds, 16X. Similarly, if I say displacement covered in first second, second second, first second, X. This would be 3X, this would be 5X, third second. This is the displacement in 3 seconds. This is the displacement in third second. This is the displacement in 4 seconds. This is the displacement in fourth second.

[00:02:46]Now, so many times questions have been asked on this ratio. So, you can say height covered in 1 seconds is to 2 seconds is to 3 seconds is to 4 seconds.

[00:02:55]It would be X, 4X, 9X, 16X, 25X, and so on. Similarly, height covered in the first second, second second, third second, fourth second, it would be X, 3X, 5X, 7X, 9X.

[00:03:09]So many times, even once this question was asked directly, find this ratio, this ratio.

[00:03:15]Then, my dear NEET aspirant, there is a question. It says an object started with initial velocity zero, acceleration constant. So, it has fallen in the first 10 seconds, it has fallen the distance of S1. It says S1.

[00:03:28]Okay? And in the next seconds, in the in the in the first 20 seconds, it has fallen the distance of S2. What will be the ratio of S1 and S2? You would be saying, "Sir, displacement in first 10 seconds is to displacement in first 20 seconds. It would be X is to 4X." So, displacement is going to be in this particular case X is to 4X. Now, if I say, "What is the displacement in first 10 seconds?" X. "What is the displacement in next 10 seconds? That would be 3X. So, that would be X is to 3X. So, if you find total, it would be 4X. If you find this, it would be 3X.

[00:04:02]This is how you guys are supposed to apply this ratio.

[00:04:05]Then, my dear NEET aspirants, you have next concept that is position-time graph.

[00:04:09]Let's suppose you have an you have a car over here. You have a car over here.

[00:04:14]This car is moving. After T is equal to 1 seconds, it is displaced position is 1. T is equal to 2, its position is 2. T is equal to 3, position is 3.

[00:04:23]Now, guys, if you plot its graph, its graph would be something like this.

[00:04:27]Now, if I say what is the slope of this graph? Slope, you always remember is tan theta. Tan theta means perpendicular divided by base. So, that means velocity delta X by delta T. So, directly remember, slope of position-time graph gives us velocity. Now, if I say, boys and girls, you have position-time graph of two cars, car A and car B.

[00:04:50]Now, this is the position-time graph.

[00:04:52]You have to compare the velocity of two cars. Sir, velocity in case of position-time graph is slope. So, you say slope of A divided by slope of B.

[00:05:01]Now, how much angle this A is making?

[00:05:03]Sir, this is making 30°. Now, if this is 30, this is 15, this is 15, so total is 60°. So, B is making 60. So, slope of A by slope of B, tan of 30 divided by tan of 60. So, it is going to be 1 divided by 3 in this particular case. Yes?

[00:05:19]Next important relation, my dear NEET aspirants. Next concept. Relation between horizontal range and maximum height.

[00:05:27]When you throw an object in a projectile motion, this is called a horizontal This is the maximum height. This is the horizontal range. Between these two, relation is H is equal to R tan of theta divided by 4.

[00:05:42]Now, guys, this is what you guys are supposed to remember. Theta is the angle at which you have launched this projectile. That is basically the theta angle.

[00:05:50]Now boys and girls, listen to me very carefully.

[00:05:54]Listen to me very carefully. You have a question of JAY 2024 on this one.

[00:05:59]In this particular case, you have launched an projectile at an angle theta. You have to find this theta.

[00:06:06]Height is given as H and and height is equal to its range. Basically, height and range in this case are equal.

[00:06:13]So, you'll be using this. H is equal to R tan theta divided by 4. So, instead of you'll be putting H instead of R you'll be putting H because in the question H is given as R. So, H and H will be cancelled. So, tan theta will be 4.

[00:06:26]Theta will be tan inverse of 4. So, this is the question of JAY 2024.

[00:06:31]Next concept is a rain man problem.

[00:06:34]Sorry, a reverse a river man problem or river swimmer problem. Now guys, let's suppose this is the river over here.

[00:06:41]River is flowing.

[00:06:43]The person has to cross the river in the minimum time. Listen to me very carefully. So, the person will dive into the river with velocity of man. It is its It is his own velocity. Since river is also flowing, river has the velocity of VR, velocity of river.

[00:06:58]Now, when person dives into the water, he has his own velocity and due to the water also he has the velocity of VR.

[00:07:06]Now, he is having two velocities, VR and we say VM.

[00:07:09]Now, the resultant of these two velocities is basically Vnet.

[00:07:13]So, the when the So, when the person dives into water, he wants to cross directly to the opposite point, but due to the river velocity, he will be dragged and he will reach this point.

[00:07:23]This is what we call the drift created.

[00:07:26]How much he will be drifted? He was expected he will land onto this point, but he eventually land on landed onto this point because of the river velocity. Now, if somebody says, "With what velocity person is crossing?" With this velocity person is crossing. That is velocity of man because it is directly a straight.

[00:07:43]And with this velocity, this drift is being created. If somebody asks, "What is the value of the time in which it is going to cross?" So, that minimum time is going to be D divided by VM, distance upon velocity. D is the width of the river, and velocity of man is the velocity of man over here.

[00:08:01]And if somebody says, "How much is the drift created?" Drift will be velocity into time. So, velocity with which velocity? VR, because due to VR only drift is being created in this particular case, my dear NEET aspirant.

[00:08:13]So, you can say VR into T. And T you recently got that is D divided by VM, you can put it over here.

[00:08:20]Even if I ask you, "What is the value of this net velocity?" Net velocity is going to be under root of VR squared plus I would say VM squared. These are the three things you guys are supposed to remember in this one. Like this is a previous year question.

[00:08:33]A person basically crosses the river with a velocity of man, his own velocity is four.

[00:08:41]Velocity of river is two. Okay?

[00:08:44]And width of the river is I would say four.

[00:08:46]And these are miles, okay? Miles per hour.

[00:08:49]Now, in this case you guys are supposed to say, "Person basically started diving, so he reached onto this point.

[00:08:55]How much will be the drift created?" So, drift is simply distance upon First, you find time, minimum time. Find the time in which he crosses the river. That is distance upon velocity of man. How much is the distance? This this this is four miles, four divided by four. So, it will come out to be one hour.

[00:09:13]Now, if I say drift, drift is VR into time. So, VR, that is two. Time came out to be one, two into one, that is two kilometers, okay? Two miles, two miles, two miles.

[00:09:25]Next, my dear NEET aspirants, this is the next concept. That is motion of a connected body system.

[00:09:31]If you have a connected body system something like this, this is a block.

[00:09:35]This is a block.

[00:09:37]And you're pulling this with a force of 20 N.

[00:09:41]And here in this rope, tension is being created.

[00:09:44]So, they will ask you two questions only in this case. Find the acceleration of the system and find the tension. When you have to find the acceleration, you'll be simply saying net pulling force divided by net mass. What is the net pulling force over here? That is 20.

[00:09:58]Net mass is 6 + 4 is 10. So, 20 by 10, that is 2.

[00:10:02]Now, if you have to find the tension, you can consider any block. Let's suppose we consider this block. So, consider this 4 kg block, okay? On this 4 kg block, tension is acting. Now, you can use Newton's second law. Force is equal to mass into acceleration. So, instead of force, I can write tension T because T is pulling. So, T is equal to mass. Mass is 4. Acceleration is 2 because this two is for this also, this also, for the entire system also. So, this is 8 N. So, with this, you got 8 N.

[00:10:32]If let's suppose you have similar question of this pattern. You have these three blocks.

[00:10:37]Now guys, here first you have to find the acceleration and tension in this string T1, tension in this string T2.

[00:10:43]Guys, see.

[00:10:44]Here in the downward direction, mg will act. That is 5g. Here, 3g will act. And here, tension T1, here tension T2. First of all, what is the pulling force over here? Sir, pulling force is 5g and 3g over here.

[00:10:57]So, acceleration is net pulling force.

[00:11:00]5g - 3g divided by net mass. 5 + 2 + 3.

[00:11:04]Okay? And then, my dear NEET aspirant, this will come out to be 2 m/s ^ 2.

[00:11:09]Now, if you have to find the tension T1, consider this block. So, you consider this this block. In the upward direction, tension is T1. In the downward direction, 5g.

[00:11:19]And acceleration is downward. That is A.

[00:11:22]Apply net force Newton's second law. Net force is equal to mass into acceleration. Now, net force will be since this is greater than this because body is coming down. So, mg is greater than T. So, 5g - t1 is equal to mass into acceleration. This is net force.

[00:11:37]This is mass into acceleration. So, from this you can find t t1. Similarly, if you have to find t2, you can consider this block that is mentioned over here.

[00:11:46]You can check it from your end.

[00:11:48]Then, boys and girls, you have next concept that is called angle of repose.

[00:11:52]Now, what is angle of repose? We say it is that angle after which the body starts sliding down.

[00:11:59]Like, if you have a block over here.

[00:12:02]Now, this block when it is about to slide down. Guys, see. If you keep on increasing the angle, the block is still not sliding down until and unless when the block starts falling down, we say the angle, that minimum angle is what we call the angle of repose.

[00:12:21]That angle when the body starts sliding down is called angle of repose.

[00:12:25]Now, three things you guys are supposed to understand here. Case one. If tan of theta is equal to mu s. Mu is the coefficient of friction between the surface and the block.

[00:12:36]If tan of theta is equal to mu s, then we say body is about to slide. Directly remember. If tan of this theta came out to be equal to mu s, coefficient of friction, body is about to slide. Next.

[00:12:50]If tan of theta is less than mu s, body will not slide. Body will not slide. If tan of theta is greater than mu s, then my dear NEET aspirants, body will slide and body will accelerate and it will have the acceleration of g sin of theta minus mu k cos of theta.

[00:13:11]This is going to be the acceleration of the body. Like here.

[00:13:14]In this particular case, first and the foremost thing, they say in the question when the block is about to slide, in that particular case, we say tan of theta is equal to mu. You have to find theta. Basically, a block is present on this uh uh inclined plane. It says, "Find the value of theta if mu is given as this."

[00:13:37]And condition is body just slides down.

[00:13:39]When body just slides down, in that case, tan theta is equal to mu. So, put tan theta is equal to mu.

[00:13:46]Mu is uh root three. So, we say tan of 60. Tan tan cancels, theta will come out to be 60.

[00:13:54]Pulling force.

[00:13:55]Let's suppose if you have a block.

[00:13:58]If I say, "How much should be the minimum force applied on the block so that the body starts move?"

[00:14:06]How much should I apply minimum force so that the body should be moving? Start moving. It is mu mg divided by cos theta minus mu sine theta. You can write it like this also.

[00:14:18]Mu mg under root of divided by under root of 1 plus mu square.

[00:14:23]Now, guys, question on this one.

[00:14:25]You are supposed to find the value of this minimum force, and value of mu is given as 3 by 4.

[00:14:31]You'll be using this mu mg upon under root of 1 plus mu square. Mu is 3 by 4. Mass of this block is 10 kg, g is 10, and 1 plus this 3 by 4 whole square, it comes out to be 16 N.

[00:14:45]Hanging chain problem.

[00:14:47]Now, guys, you have got over here a chain which is placed on the horizontal table.

[00:14:53]Now, this is the minimum length of the chain which is hanging over here.

[00:14:58]If you further increase this hanging portion, it is going to slide down.

[00:15:04]So, what does it say? How much can be the maximum length, not the minimum, sorry, maximum.

[00:15:11]How much can be the maximum length of the chain that can over long? Maximum length. So, maximum length of the chain that can over long is mu into L upon 1 plus mu.

[00:15:22]Sir, can we find the value of mu also from here? Yes, you can find the value of mu also from here.

[00:15:27]Now, there is a question on this one.

[00:15:29]Value of mu is given as 0.25.

[00:15:33]A chain is hanging on the table.

[00:15:35]It says what should be the maximum length of the chain which is hanging, X?

[00:15:40]So, you say that is mu into L upon 1 + mu. What is the value of mu? 0.25 into L upon 1 + 0.25. Now, solve this, it will come out to be L by 4.

[00:15:49]It is L by 4.

[00:15:51]Yes.

[00:15:52]One more important thing. Area under force displacement graph.

[00:15:56]If you have force versus displacement, the graph is something like this. This area basically gives you the work done.

[00:16:03]Directly remember.

[00:16:05]Area under force displacement graph gives you the work done.

[00:16:09]Now, this is a question. This is a previous year question. Force versus displacement graph. You have to find the work done. So, you'll be basically finding this area minus this area.

[00:16:18]Always remember, upper upper area minus lower area. Upper area means this area of triangle, area of this rectangle, area of triangle minus area of triangle minus area of rectangle. It is done over here and it is 5 J is the answer in this case.

[00:16:33]Next.

[00:16:34]Work done by spring.

[00:16:36]Next concept. Work done by spring. My dear NEET aspirants, in this particular case, there is a spring, you have got a spring and a block is attached to this.

[00:16:45]If you elongate the spring, if you move the block from X1 to X2, means you have done work. How much work you did in taking the block from X1 to X2? It is minus 1 by 2 K X final squared minus X initial squared. This is going to be the work done if you take the block from X1 to X2. If you take the block from X1 to X2. Like there is a question.

[00:17:07]We are elongating a spring from X is equal to 0 to X is equal to 2. You have to find the work done. Minus 1 by 2 K X final squared. X final is 2 squared minus zero. So, it comes out to be minus 2K.

[00:17:20]Then the question says, "Further you elongated this block, further you elongated the spring from two to four."

[00:17:26]Now, what will be the final work done? W dash is equal to minus 1 by 2K final square, four square minus initial.

[00:17:33]In this case, initial is two. So, when you solve this, it comes out to be 3W.

[00:17:38]3W.

[00:17:40]I hope this is also clear. Okay, one more important concept, work energy theorem.

[00:17:45]My dear NEET aspirants, what does work energy theorem say?

[00:17:48]Work energy theorem says, work done by all the forces is equal to change in kinetic energy. You can write it like this. Work done by all the forces change in kinetic energy, final kinetic energy minus initial. And you can write it like this also, 1 by 2 M V final square minus V initial square. Now, boys and girls, there is a question which I have put on this particular concept. See.

[00:18:08]A body is basically moving, its position is given.

[00:18:13]You are supposed to find work done. You will be applying work done is equal to change in kinetic energy.

[00:18:18]Now, in change in kinetic energy, that is 1 by 2 M. M is the mass of the body, V final square, final velocity, initial velocity square.

[00:18:26]From this position, when you differentiate, you get velocity. At T is equal to zero, you get initial velocity.

[00:18:33]At T is equal to three seconds, you get final velocity. Because it says, "Find the work done from T is equal to zero to T is equal to three." When you get initial and final velocity, you'll be putting it over here. Final velocity square, that is three square, initial velocity square, that is zero. And when you solve it, comes out to be this.

[00:18:49]There is one more question I have put up on this one. Please do have a look for on this question from your end.

[00:18:55]Next.

[00:18:56]Potential energy with respect to the reference line.

[00:18:59]My dear NEET aspirants, let's suppose this is a reference line, surface.

[00:19:03]Usually, we take the surface of the earth. Or it completely depends upon you, whatever you take the surface line.

[00:19:08]We say potential energy on the surface line is zero. Above the surface we consider potential energy of the object.

[00:19:15]If this is mass M, its potential energy will be MGH.

[00:19:18]Below the surface line we consider potential energy minus MGH, minus MGH.

[00:19:24]Now, if I say there is a rod, this is another rod, what will be the potential energy of this rod? Guys, you will be assuming the mass of this rod at its center of mass at what distance? L by 2.

[00:19:38]So, what will be the potential energy? M G and instead of H you'll be putting L by 2. Here, minus MGL by 2.

[00:19:48]One more important thing, power.

[00:19:50]Power.

[00:19:51]Power.

[00:19:52]So, we say power is basically F dot V.

[00:19:56]Dot product of force and velocity gives you the power or we say FV cos of theta.

[00:20:02]Now, there is a question on this one which was asked in NEET 2023.

[00:20:05]An object is moving which has this velocity.

[00:20:09]It has this forces acting on. You are supposed to find power. Power is F dot V. Do the dot product of two vectors.

[00:20:15]Like dot product is coefficient of this multiplied by coefficient of this. 5 into 10, 50. Minus 3 into 10, that is 30. Plus 6 into 20, that is 120. So, power is 140 watts. So, guys, these were all the concepts. Make sure you smash the like button and you share it with your friends also. Thank you so much.

[00:20:32]Take care and bye-bye.