As-Salamu alaikum everyone and today we are going to be talking about kinematics. You see in classical physics we will be discussing mainly classical mechanics. Mechanics are comprised of two main categories that are kinematics which is the study of motion with this regard to any forces involved and dynamics is the study of motion with forces involved and it deals with forces. And kinematics was mainly developed by Galileo Galilei whereas dynamics was developed further by Sir Isaac Newton. And this was a very important start so let's start with kinematics. Kinematics was a very important subject to start on physics because before the study of motion to kinematics we would think that math only worked in space not on earth. Now there was a bit of a concept about math sort of working on earth but it wasn't developed until Galileo where he came up with equations and explained the motion of objects on earth. Now this was amazing because math would now work on earth. Here's the thing. In earth we have a lot of forces involved that's why we have dynamics. We have friction, we have gravity, we have weight, we have a life force, we have tons of objects around each other each exerting its own force which means our values won't be 100% accurate. There will be some deviences but for as far as kinematics is concerned the values will be accurate enough. As we're discussing motion through mathematical means we have to introduce ourselves to certain variables. So here are some of the variables. First we have displacement. Displacement or position is depicted with either d or x. Then there is velocity which is depicted with v. At acceleration with a and finally time with t. There are also subscripts we have to ensure. So v0 or vi means initial velocity and vf or vt means final velocity and same applies to position. Now that we've got those variables out of the way here are the kinematic equations that we can use. As you can see there is one, all these equations have at least one variable missing which is important for some questions and some circumstances. So imagine you're in a race course. You turn your car from at rest to a certain velocity for 30 seconds pressing on the accelerator. You accelerate at 2 meters per second squared. So two questions. One what is your final velocity and two how far did you travel and here we will be using two equations. Let's first find out the question well what is the final velocity. So vt is equal to vi plus at. So we just jump 0 meters per second plus two meters per second squared plus 30 seconds and we get a total of 60 meters per second which is right around 216 kilometers per hour. As for the second one we can disregard the first two terms because they add up to 0. So position with respect to time is one half of acceleration times times squared which gives us a total of 900 meters. So that was a very easy example. Let's go with another one continuing the race course and then we'll have a practice problem. So say you take a corner. The car is already in motion. When you exit the corner you travel at 82 meters per second which is almost 295 kilometers per hour but your car is sprung out of control. So you slam the brakes at negative 8 meters per second squared until you go 70 meters per second instead which is 252 kilometers per second where your car is stable. 8. How long did the car take to slow down and be how far did it travel until it reached the desired velocity. So first we use this simple equation that we used. Then we take 70 meters per second and all that then we solve for time. Remember algebra? Yeah. And as you can see both numerator and denominator has negative signs which is convenient for us. So we're correct. And we get 1.5 seconds. You realize this is less than two seconds because of how much the deceleration was. So number B. So B we use the position equation. Here we will not use the first term but we will use the second term, V-I-T because the car was already in motion. So we take 82 meters per second times 1.5 seconds plus 1 half of negative 8 meters per second squared times 1.5 second squared. And we get 123 meters minus 9 meters which is 114 meters. So that is all for this first part of our kinematic series. In our next video we will be discussing vertical velocity where it's going to be a little interesting and easier because acceleration is literally constant. So that's all there is to it. Thank you for watching. Please like the video, subscribe and share it to anyone who might need it and comment down below to anything I've missed or anything I could improve or something you'd like to see. And thank you for watching and I will see you next time. Bye.