Introduction to Vectors and Scalars

by Patrick Ford
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Hey, guys. So in this video, I'm gonna introduce you to two types of measurements that you'll need to know called vectors and scale er's Let's check it out. So whenever we take measurements in science, we're always gonna get the magnitude. For example, let's say you take a thermometer outside and you measure the temperature to be F, or you measure a box and your way to be 10 kg. The magnitude is really just the size of the measurement. You can think about the size as just the number, and so the size or the number of the measurement is the magnitude at 60 and the 10 and then just have the units. But some measurements are a little bit more specific. Some measurements also give us direction. For example, let's say you're describing where you walked outside and you say I walk 10 m to the right or let's say you're describing where you're driving and you say you're going 20 miles an hour to the north. So both of those things are examples of direction. And so let's go through a bunch of examples to make this stuff really, really straightforward. So let's say you weigh in apple in it weighs 5 kg. You're measuring the quantity of mass. The 5 kg represents the magnitude, but it doesn't make sense to ask which direction those 5 kg go, so we don't have direction there. What about days, days or 24 hours long? So we're measuring a time there her 24 hours or magnitude, but it doesn't make sense to ask which direction Those 24 hours ago. Now we already talked about this one. It's 60 degrees outside, so 60 degrees is a measurement of temperature and we have the magnitude. But it doesn't make sense to ask which direction to those 60 degrees go in. So we don't have direction there now for this last one here, I pushed with 100 Newtons to the left. When you're pushing something, you're measuring the force. The 100 Newtons is the magnitude, and here it actually does make sense to ask which direction you're pushing that could affect things. Are you pushing the box or whatever you're pushing to the right to the north, to the left. So here we do have a direction. And so, in physics measurements with direction are called vectors. So, for example, force has magnitude and direction. So it is a vector, whereas measurements without direction are called scale er's. So, for instance, mass time and temperature since they have magnitude on Lee and not the direction these air examples of scale er's. So let's take a look at to sort of related ideas or related measurements. I walked for 10 ft, so let's say you talk to your friend. You said I walked for 10 ft so that you have the measurement right here. That's the magnitude. But you're not specifying which direction you went in. You could have gone five to the right five to the left. You could have gone 10 and whatever direction. And so we don't have the complete idea of that measurement, whereas now let's say you talk to your other friend, you say, Well, I walked 10 ft towards the east direction, so now you have the magnitude and the direction, so we know that this one's gonna be the vector, and this one is going to be the scaler. And so in physics, there's two special words for these measurements. I walked for 10 ft, is called the Distance the scaler version of it. Whereas the more complete picture, the vector is called The displacement. And both of these words here answer the question. How far did you go? Now let's take a look. The last two I drove for 80 MPH or I drove for 80 MPH to the west. So 80 MPH is our magnitude, but doesn't give us the direction. You could have gone 80 MPH to the south, to the west, east, North you don't have with the direction is versus this sentence over here I drove 80 MPH to the west. Gives us more information and more complete idea of what that motion or measurement is. You have magnitude and direction. So just like the other two, this one's gonna be vector, and this one is gonna be the scaler. And we have two special words for these measurements as well. This one, that scaler is gonna be called the speed and the vector is gonna be called the velocity. Both of these words here answer the question. How fast did you move or did you go and, um, the other thing to remember is that or one thing to make? The easy to remember is that the velocity V is the vector and speed with s is the scaler So v with the s with s Hopefully guys, I painted a really, really clear picture of the difference between vectors and scholars. So that's it for this one.