in this video we're going to go through how to do metric conversion involving
one prefix like picosecond going to second, meter going to megameter,
centimeter cube going to meter cube, just to name a few.
I'm going to share with you a foolproof method and tips to make sure you'll be
able to do the conversion successfully. Let's get to know some of the common
SI prefixes. I've included 12 of them from tera all the way to pico.
Depending on your school, you might need to memorize them. Tera, giga, mega,
all the way to pico, those are the names of the prefixes and the numbers are the
value for each of the prefixes. For example, 10 to the power of 12 that is
the value for tera. 10 to the power of 9 for giga and so on and so forth.
I've also included in base which has a value of 10 to the power of 0 which is the
same as 1. Sometimes when you see prefixes being used they are abbreviated
like this. Like capital T to represent tera, small letter d to represent deci.
So how do we use prefix and base? Let's take kilometer for example. That's a unit
for distance, so meter in this case is the base unit. k which stands for kilo
is the prefix. To make life easy I came out with a mnemonic to help you remember
all the 12 prefixes. That should help you remember the name of the prefixes in the correct order.
The great man King Henry's daughter, Beth, drinks cold milk until nine pm.
I've worked off from the abbreviation
for each of the prefixes starting from tera all the way to pico.
As for the numbers on the exponent we will start off with 0 for base and then 1 2 3 6 9 12
on each side.The difference between the left side and the right side on the
deci centi milli all the way to pico, there's negative sign in front, so if you
remember, The great man King Henry's daughter, Beth, drinks cold milk until nine pm
and then you go from 0 1 2 3 6 9 12 .
Do that on both sides and then make sure you put in the negative sign for the right-hand
side which is deci all the way to pico and you'll successfully memorize
all 12 SI prefixes. Hope this helps. Now that we know our prefixes let's proceed
to the metric conversion. I went through a foolproof method of unit conversion in
a video I've posted. The link is on the top right corner and in the description
box below. Do check it out if you haven't seen it so we're going to proceed using
this method and so let's start with our first example. Question is asking us to
convert 936 picosecond to second. If you recall from our SI prefixes, the value
for pico which is p it's 10 to the power of negative 12 so what this means is,
1 picosecond is 10 to the negative 12 s. Second is the base unit in this case.
Pico is the prefix so we're trying to convert picosecond to second. Now that
we know the conversion factor we can easily convert. Start with what is given
which is 936 picosecond. Multiply, draw a line across place the unit that you want
to get rid of at the bottom which is picosecond and then place the unit that
you want which is second on the top. Pico second will cancel each other off and
then after that we place in the values from our conversion factor. We have one
in front of picosecond 10 to the negative 12 in front of s, so we do the
math 936 times 10 to the power of negative 12 divided by 1 that will give
us 9.36 times 10 to the power of negative 10 seconds.
Let's try on another example. Convert 25 meter to megameter.
So the question is asking us to convert from meter to megameter. Again from the
prefix table mega the value is 10 to the power of 6 so what this means is
1 megameter is 10 to the power of 6 meter. Meter is the base unit in this case, so,
start with what we have which is 25 meter multiply draw a line across, put
meter at the bottom and megameter on the top because we want to cancel off
the meter giving us megameter and then we place in the values in front of the units.
1 in front of megameter, 10 to the power of 6 in front of meter so that
gives us 25 times 1/10 to the power of 6. If you punch it in your calculator or if
you can do mental math that will give us 2.5 times 10 to the power of
negative 5 mega meter. Moving on to our third and final example, it's slightly
more difficult than the last two that we've tried. So this question is asking
us to convert 25 meter cube to mega meter cube. The previous example we were
asked to convert from 25 meter to megameter. Do you see the difference?
Do you think we're going to get the same answer like the last one which is 2.5 times 10
to the power of negative 5 except for the unit now we'll be mega meter cube?
Well, stay tuned and we're gonna go through the calculation. Let's start with
the prefix mega. Mega is 10 to the 6 so 1 megameter is 10 to the 6 meter, then we
start with what's given which is 25 meter cube and then we multiply draw a
line across and then we place meter at the bottom and megameter at the top
because we want to try and cancel off the meter so we place the meter at the
bottom and we place in the values for the conversion factors so far is the same
steps as the previous example but now notice that the unit for 25 is meter cube.
So that means we need to cube everything as well so that meter cube
will cancel off meter cube like this. So, let's simplify now, we have 25 times 1
divided by 10 to the power of 18 because we cube the exponent 10 to the 6
so 6 x 3 gives us 18 and then the meter cube can now cancel off each other and
we do the math we get 2.5 times 10 to the power of negative 17 megameter cube.
That is definitely not the same as the answer that we got from the previous
example this kind of conversion that involves cube or square a lot of people
make mistakes when trying to solve this because they
miss out that cube part. So when you perform calculations that has cube or
square, please make sure after you've placed in the conversion factor.
Make sure you cube it or you square whichever that's appropriate. So we went through
three examples together. Why don't you try one out on your own?
Try converting 0.028 nanometer to meter. I'll place the answer in the description box below.
Thanks for watching, I'll see you in the next video.
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