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Learn about Speed translation

Learn about Speed translation Welcome to the presentation on units. Let’s get started. So if I were to tell you—let me make sure if my pen is setup right. If I were to tell you that someone is let’s say they’re driving at a speed let’s say it’s Zack. And they’re driving at a speed of—let me say 28 feet per minute. So what I’m going to ask you is, if he’s going 28 feet in every minute, how many will Zack travel in 1 second inches. So how many inches per second is he going to be going? Let’s try to figure this one out. So let’s say if I had 28 ft, short for feet, feet per minute, mins short for minutes. So 28 feet per minute let’s first think how many inches per minute that is. Well, we know that there are12 inches per foot, right? If you didn’t know that, you do now. So we know that there are 12 inches per foot. So if he’s going 28 feet per minute, he’s going to be going 12 times at many inches per minute. So 12 times 28—let’s see, let me do a little work down here—and this kind of stuff—it will be okay to use a calculator although it’s always good to do the math yourself it’s a good practice. So that equal 336 inches per minute. And something interesting happened here is that you notice that I had a foot in the numerator here and I had a foot in the denominator here. So you can actually treat units just the same way that you would treat actual numbers or variables that you have the same number in the numerator and you have the same number in the denominator and you’re multiplying not adding you can cancel them out. So the feet and the feet canceled out and that’s why we were left with inches per minute. I could have also written this as 336 foot per minute times inches per foot and because the foot per minute came from here and then I will cancel this out and now we got inches per minute. So anyway, I don’t want to confuse you too much with all of that unit cancellation stuff. The bottom line is you just remember well if I’m going 28 feet per minute, I’m going to go 12 times that many inches per minute right because they’re 12 inches per foot. So I’m going 336 inches per minute. So now, I have the question but we’re not done because the question is how many inches, am I going to be traveling in one second? So let me erase some of the stuff here at the bottom. So I’m going to be going—so 336 inches per minute and I want to know how many inches per second. What do we know? We know that 1 minute—and notice I write it in the numerator here because I want to cancel it out with this minute here. 1 minute is equal to how many seconds? Equals 60 seconds, right? And this part can be confusing but it’s always good to just take a step back and think about what I’m doing. If I’m going to be going 336 inches per minute, how many inches I’m going to travel in 1 second? Am I going to travel more than 336 or am I going to travel less than 336 inches per second? Well, obviously less because a second is a much shorter period of time. So if I’m—in a much shorter of period I’m going to be traveling a much shorter distance if I’m going the same speed. So I should be dividing by number which makes sense. I’m going to be dividing by 60. And I know this can be very confusing in the beginning but that’s why I always want you to think about should I be getting larger number or should I be getting a smaller number that always give you a good reality check. And if you always want to look at how it turns out in terms of units, we know from the problem that we want these minutes to cancel out with something in get it into seconds. So if we have a minute in the denominator in the units here, we want to a minute in the numerator here and a second and a second in the denominator here and 1 minute is equal to 60 seconds, so here, once again the minutes and the minutes cancel out and we get 336 over 60 inches per second. And now, if I were to actually divide this out, we could see—actually we could just divide the numerator and the denominator by 6, 6 goes in the 336, 56 times over 10 and we can divide that again by 2 so the 0614 it is 28 over 5. And 28 over 5—so this equal 5.6. So I think we now just solve the problem. If Zack is going 28 feet in every minute, that’s his speed, he’s actually going 5.6 inches per second. Hopefully that kind of makes sense. Let’s try to see if we could another one. If I’m going 91 feet per second, how many miles per hour is that? Well, 91 feet per second so how many—if we want say how many miles that is, should we be dividing or should we be multiplying? Oh we should be dividing because it’s going to be a smaller number of miles. And we know that 1 mile is equal—and you might want just memorize this 5280 feet, it’s actually a pretty useful number to know and then that will actually cancel out the feet. And then we want to go from seconds to hours, right? So if we go from seconds to hours if I can travel 91 feet per second how many will I travel an hour? I’m going to be getting a larger number because an hour is a much larger period of time than a second. And how many seconds are there in an hour? Well, there are 3600 seconds in an hour, 60 seconds per minute and 60 minutes per hours. So 3600/1 second per hour and the seconds will cancel out. And then we’re just left with—we just multiply everything out. We get the numerator 91 times 3600, right? 91 times 1 times 3600 and the denominator we just have 5280. And this time around, I’m actually going to use a calculator. I’m going to bring up the calculator just to show you that I’m using a calculator. Let’s see—so if say 91 times 3600 that equals a huge number divided by 5280, 62.05. So that equals 62.05 miles per hour.

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Learn about Speed translation

Welcome to the presentation on units. Let’s get started. So if I were to tell you—let me make sure if my pen is setup right. If I were to tell you that someone is let’s say they’re driving at a speed let’s say it’s Zack. And they’re driving at a speed of—let me say 28 feet per minute. So what I’m going to ask you is, if he’s going 28 feet in every minute, how many will Zack travel in 1 second inches. So how many inches per second is he going to be going? Let’s try to figure this one out. So let’s say if I had 28 ft, short for feet, feet per minute, mins short for minutes. So 28 feet per minute let’s first think how many inches per minute that is. Well, we know that there are12 inches per foot, right? If you didn’t know that, you do now.

So we know that there are 12 inches per foot. So if he’s going 28 feet per minute, he’s going to be going 12 times at many inches per minute. So 12 times 28—let’s see, let me do a little work down here—and this kind of stuff—it will be okay to use a calculator although it’s always good to do the math yourself it’s a good practice. So that equal 336 inches per minute. And something interesting happened here is that you notice that I had a foot in the numerator here and I had a foot in the denominator here. So you can actually treat units just the same way that you would treat actual numbers or variables that you have the same number in the numerator and you have the same number in the denominator and you’re multiplying not adding you can cancel them out. So the feet and the feet canceled out and that’s why we were left with inches per minute. I could have also written this as 336 foot per minute times inches per foot and because the foot per minute came from here and then I will cancel this out and now we got inches per minute. So anyway, I don’t want to confuse you too much with all of that unit cancellation stuff. The bottom line is you just remember well if I’m going 28 feet per minute, I’m going to go 12 times that many inches per minute right because they’re 12 inches per foot. So I’m going 336 inches per minute.

So now, I have the question but we’re not done because the question is how many inches, am I going to be traveling in one second? So let me erase some of the stuff here at the bottom. So I’m going to be going—so 336 inches per minute and I want to know how many inches per second. What do we know? We know that 1 minute—and notice I write it in the numerator here because I want to cancel it out with this minute here. 1 minute is equal to how many seconds? Equals 60 seconds, right? And this part can be confusing but it’s always good to just take a step back and think about what I’m doing. If I’m going to be going 336 inches per minute, how many inches I’m going to travel in 1 second? Am I going to travel more than 336 or am I going to travel less than 336 inches per second? Well, obviously less because a second is a much shorter period of time. So if I’m—in a much shorter of period I’m going to be traveling a much shorter distance if I’m going the same speed. So I should be dividing by number which makes sense. I’m going to be dividing by 60. And I know this can be very confusing in the beginning but that’s why I always want you to think about should I be getting larger number or should I be getting a smaller number that always give you a good reality check.

And if you always want to look at how it turns out in terms of units, we know from the problem that we want these minutes to cancel out with something in get it into seconds. So if we have a minute in the denominator in the units here, we want to a minute in the numerator here and a second and a second in the denominator here and 1 minute is equal to 60 seconds, so here, once again the minutes and the minutes cancel out and we get 336 over 60 inches per second. And now, if I were to actually divide this out, we could see—actually we could just divide the numerator and the denominator by 6, 6 goes in the 336, 56 times over 10 and we can divide that again by 2 so the 0614 it is 28 over 5. And 28 over 5—so this equal 5.6. So I think we now just solve the problem. If Zack is going 28 feet in every minute, that’s his speed, he’s actually going 5.6 inches per second. Hopefully that kind of makes sense. Let’s try to see if we could another one.

If I’m going 91 feet per second, how many miles per hour is that?

Well, 91 feet per second so how many—if we want say how many miles that is, should we be dividing or should we be multiplying? Oh we should be dividing because it’s going to be a smaller number of miles. And we know that 1 mile is equal—and you might want just memorize this 5280 feet, it’s actually a pretty useful number to know and then that will actually cancel out the feet. And then we want to go from seconds to hours, right? So if we go from seconds to hours if I can travel 91 feet per second how many will I travel an hour? I’m going to be getting a larger number because an hour is a much larger period of time than a second. And how many seconds are there in an hour? Well, there are 3600 seconds in an hour, 60 seconds per minute and 60 minutes per hours. So 3600/1 second per hour and the seconds will cancel out. And then we’re just left with—we just multiply everything out. We get the numerator 91 times 3600, right? 91 times 1 times 3600 and the denominator we just have 5280. And this time around, I’m actually going to use a calculator. I’m going to bring up the calculator just to show you that I’m using a calculator. Let’s see—so if say 91 times 3600 that equals a huge number divided by 5280, 62.05. So that equals 62.05 miles per hour.

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