RAHASIA BENDA BISA GERAK?! 🤯 | KINEMATIKA Kelas XI SMA Fisika

Have you ever heard of kinematika? It looks complicated, right? But today, we will clear the way for two of our physical materials sources without the jargon that makes us dizzy. We will translate the language of the universe into everyday language. So, we can really understand what happens when a thing moves from point A to point B. Let's just start this exciting exploration.

But before we go any further, I want to challenge your thoughts. Just imagine, if someone runs as fast as a horse, around a 400-meter-long path, until they're sweating and nauseous, then they stop exactly at the start line where they started. The question is, physically, is he actually moving? Hold on to your answers first, okay? Because what we're going to discuss in a moment may change your view on movement in total.

Well, for our navigation, this is the concept map. Just three stops. First, we discuss the position, distance, and movement. Then we go to speed versus speed and acceleration. And lastly, we discuss the question of straight movement, aka GLB and GLBB. Oh yes, be prepared, because in the middle of the explanation later, I will give a surprise quiz to test how far you understand.

Okay, our first stop: Position, Distance, and Transition. So, the basic rules of play are: all movements must be evaluated based on the change of position from a certain point of reference. If there is no reference point, we will not know whether the object is moving or not. Well, this fly illustration that is hungry is really right to explain it. Try to see the blue line. It shows the route of the fly that wanders around looking for a permit.

try to pay attention to the red line. That is the straight route that is the most efficient from the starting point to the destination. The difference is so big, isn't it? Between the messy road that we take and the final point that we really reach,

From there, we get the golden rule. The distance is like calculating all the steps that the ant took. No matter how long the path is, it's all calculated. It's different from the transition. The transition is very firm. It only cares where you start and where you stop. Just pull one straight line. Remember the crosshairs earlier? Even though the distance is 400 meters, because it returns to the starting point, the transition is zero. Physically, it is considered not to change at all. Amazing, right?

Sekarang, waktunya pause ending pertama kita. Coba deh, beneran dijadah sebentar. Perhatiin jalur pesepeda di layar. Kalau titik O itu adalah posisi 0 km di jam 7 pagi, terus dia goes sampai di titik B di angka 15 km pada jam setengah 9, coba hitung, berapa total jarak yang dia goes versus perpindahan aslinya dari titik acuan awal? Ini teka-teki logika yang asik banget buat pemanasan otak. Gimana, udah dapat jawabannya? Sip, mari kita lanjut.

Let's move on to the second stop, speed versus speed and acceleration.

If we've talked about how far things move, now we need to know how fast they get. Do we often use the word "speed" and "speed" when we talk? But in physics, these two things are very different. Speed is just a normal number, aka the scale, which is calculated from distance divided by time. But speed? Well, this is obtained from the shift divided by time. Speed is the factor,

It means you have to have a direction. So if you say drive 100 km/h to the north, that's the speed. If you don't mention the direction, it's just a speed. In fact, in the real world, we rarely walk at constant speed. That's why we need a concept of acceleration. Easily, acceleration is the process of accelerating or slowing down our movements. This value shows how much your speed changes every second.

If you're kicking the gas pedal or the car, then you're playing with what we call acceleration. As promised, this is our mid-session quiz to clear your mind.

There's a classic question. Imagine there are two cars, the distance is 75 kilometers apart. Then they go straight to each other at the same exact time. The first car has a speed of 90 kilometers per hour, the second 60 kilometers per hour. The question is, when and how many kilometers will they pass? Come on, let's try to draw a line for a moment.

Okay, let's look at the solutions together. The first step, because they move closer to each other, the relative speed is added. 90 + 60 = 150 km/h. Second, to find out when they meet, the total distance of 75 km is divided by the combined speed. The result is half an hour or 30 minutes.

Now, the third step, where is it? In 30 minutes, the first car that goes 90 km/h must have walked half of it, which is 45 km. Simple as that. It looks like the physics that looks complicated is actually just a simple logic puzzle, as long as we know the formula. Great! Now we are walking to the peak of our today's top of the hill, straight movement, which is equal to GLB and GLBB.

In this section, the physics starts to feel like a super power. Because imagine, we can really predict the location of a thing in the future, just by using these laws. And the coolest thing is to see the contrast of these two things. GLB is like you turn on cruise control on a empty toll road. The speed is constant and the acceleration is exactly at zero. Very smooth and very easy to guess.

On the other hand, GLBB is a dynamic movement. You constantly press the pedal, so there is a constant acceleration value that makes your speed go up and down in order every second.

Now, it's time for our second pause and think. Let's try to plot this curved graph that measures the position of time. This is a very special graphic shape for GLBB, right? My question is, logically in the physical reality, what is actually being experienced by the object when it is exactly at the top of that red curve? Try to guess for a moment and think logically.

Here's the big secret. The physics rules say this: The slope in the graph of the position against time shows the value of the speed. So when at the top of the curve curve, the graph is flat or horizontal. It means the slope level is exactly zero. Automatically, the speed of the object at that millisecond is really zero. The object literally stops for a second in the air before finally turning. Amazing, right?

Let the concept stick, try to pay attention to the shape of these two graphics. For the object that is constantly accelerated in GLBB, the speed graph of time is shaped like a straight line that continues to rise. But, as we see from the graph of position against time, the constant speed will form a curve of curved parabola that is really beautiful and very mathematical. The point is, the longer the time, the more exponentially the distance will increase.

Finally, we have reached the conclusion of our exploration. The most important thing you must remember is that kinematics is not just about memorizing dry rules that make you sleepy. Kinematics is a structural language used by the universe to precisely explain every movement that happens around us. As a reminder from this summary, I have one last caveat about vertical movement that is quite brain-twisting.

Imagine if you throw a basketball straight through the air up. Well, how fast is the ball exactly at the highest vertical point before it starts to fall again down? And what are the physical reasons? Make this basketball line as a guide, okay? I challenge you to write a hypothesis or answer your comments below. It's really fun to discuss and argue with others. If you feel you got the answer,

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