Motion

Hello everyone, long time no post! I came back with a topic "Motion". I know that you all have heard of it or even know what it is. For the people who don't know, I will talk about it today. As I start as usual, what is motion?

Motion is any movement or change in position or time. For example of motion of your body, standing up and down, blood circulation, and stomach going up and down while you are breathing are the ones. There are a lot more examples, but I am not listing thousands of them here.

 I have many things to talk about.


First, what is relative motion?'

Relative motion is when an object changes position moving relative to a reference point. So let me give you an example. When I am on a train and let’s say the train is moving forward. Outside on the window, you will feel everything out there going backward instead of you on the train, going forward. On your reference point, it will be outside that goes backward and you staying still.
relative motion
 Next thing you will learn is distance and displacement. I bet you know what distance is but not displacement, but the people who don’t know what it is…
Distance is the measurement of the path you take to get to the finish. There a lot of units to show the distance, for instance, there are mm, cm, m, km, inch, feet, and yard. Many countries use mm, cm, m, km as a main units, but in U.S we use all, which kind of drives me crazy. Just to make sure you know, there are much more units used in the distance. If I give you an example, let’s say there is 100 m race in school. You know what? As it says, the distance is 100 m. Isn't it so simple?
 
d is the displacement between (x1,y1) and (x2,y2)
Since it is easy, I will explain what displacement is now. Displacement actually includes the distance, and it is the distance between the starting and ending points and the direction in which you travel. Let’s say you are late for something. You want to go faster than it usually takes, right? Maybe you can go shortcut without going all the way around something between you and the place you want to go. The shortcut is the displacement in an easy word to displacement. You go directly to the ending point. What you need to know additionally is that displacement can be 0 even though distance is not 0. So, when you come back to the spot where you had went off, I mean you go round and come back to starting line, displacement is 0.

 

speed
Next, we are going to learn about speed. I know that you know speed because it appears a lot of time our lives. It comes out on the computer game, on the road “speed limit” or in science and in math a lot, everywhere. Do you know the definition of the speed? Okay,  the speed is the distance an object travels in a unit of time. You can calculate the speed too. It is distance over time. This might confuse you, so I will explain it to you. Let’s say the car is moving 120miles in 2 hours, and let's say you want to figure out the speed of the car.Since the equation of the speed is distance/time, you just need to stick the numbers in, and it will be 120/2 which is 60. So the car is moving 60 miles per hour which is the speed of the car.
 Do you know the difference between velocity and speed? Many people think it is same. Well, that is what I thought too. You know what? They are different. Velocity is including the direction of the object, but speed does not. To give you the example, let's think that the car is moving toward NE and move toward south. In this case, you need to ask the velocity, not speed. That is the right word to say. But when the car goes in one way not thinking the direction it's going, you must say "Speed of the car" instead of velocity of the car.
 velocity
Next lets talk about type of speeds. There is instantaneous speed and average speed. They are both part of speed. For the example, the bike is going one place to another place. Let's say that the bike went 2 km in 100 seconds. The average speed will be the average speed of the bike from the distance first to the end, 2 km. The speed will be 2000/100 which is 20 m per second. But instantaneous speed is the a little different. This is the speed at the instant time. Bike won't go 20 m per second exactly at every moment. The person could have slowed down and speed up later. So instantaneous speed can be the speed of the specific moment also the speed from 5 m to 15 m can be instantaneous speed which can be 15 m per second.


These are the ones I wanted to explain to you today. I hope you understood even though I have a bad explanations. Thank you!