In this video you are going to learn everything that you need to know to
finally conquer conversions. Alright let's do this!
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Hello Hello Melissa Maribel here and I help students like you understand what you just learned in
class so you stress less and you graduate faster so if you're new here
consider subscribing. Dimensional analysis, conversion factors, conversions, unit
conversions, [Sigh] All that means is going from one unit to the next.
These are the most common conversion factors that are specific to length, mass, volume and time.
In the description box below you'll find a link that allows you to actually
access the same conversion factors. Let's go ahead and jump into our first example
the mass of a frisbee is 125 grams convert its mass to ounces using the
conversion factor one ounce equals twenty eight point three four
nine grams you're given is the 125 grams this one is so nice to actually give you
the conversion factor of one ounce is equal to this amount of grams and we are
finding our ounces.The plan is to go from grams to ounces the proper setup is
having your given on top diagonally we'll place the grams across from each other
so our units will cancel. Grams would then cancel and we'd be left with our
ounces. You just divide these two numbers. You end up getting four point
four zero nine ounces however our given was three sig figs we need to round up
Your final answer is that four point four one ounces. Moving on to example two using
two conversion factors. How many minutes will it take to drive
to LA from San Francisco if a speed of 72 miles per hour is maintained the
distance between the two cities is 405 miles
first start with identifying you're given conversion factor or
factors and what you are finding you're given is the 405 miles our conversion
factors. We'll start with the 72 miles per hour
so per hour just meaning that it is for every one hour from there we need to
convert to minutes so we'll need the conversion factor of 1 hour equaling 60
minutes because we are then finding minutes. Your plan is starting with
you're given the miles we'll convert that to hours using the first conversion
factor then from there taking our hours and going to minutes using our second
conversion factor. The set up is starting with your given we'll have our miles on
top we want to match those miles on the bottom so they can cancel. Note that
these miles will then cancel and we'll have hours now on top you want to cancel
out our hours we'll put them across from each other
now they cancel as well and we're left with minutes multiply straight across
and divide by that 72. You get three hundred and thirty seven point five
minutes however we have three significant figures so we round up your
final answer is three hundred and thirty-eight minutes. Let's look at our
last example. A patient needs 50 milligrams of a medicine three times a
day. If each tablet of medicine contains 25 milligrams, how many tablets will the
patient need for a four-day prescription? As always you want to go ahead and start
with identifying your given, conversion factor or factors and what you are
looking for. The given is that 50 milligrams three times everyday
conversions factor is that one tablet is equal to 25 milligrams where we saw that
that said each tablet of medicine contains 25 milligrams and lastly you
are finding the total amount of tablets in that four-day prescription
Step one is to multiply your given by three take the 50 milligrams and multiply
it by the three times per day and our actual given is 150 milligrams per day
The next plan is taking our milligrams per day and changing that to tablets. The
proper setup will have our new given the 150 milligrams per every one day. Next
you want to match the milligrams to cancel them out, we'll place them across
from each other using our conversion factor. The milligrams will then
cancel and now we have tablets per day divide the 150 divided by 25 and
you get six tablets per every one day. We got that here with our tablet per every
day. The last step is then to multiply by four using the six tablets per every
day we'll cancel out our days putting them across from one another
six times four then gives us 24 tablets. Grab a pen and paper and try these
practice problems
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How was that? For conversions I do recommend practicing as many problems as
possible! In the description box below there's a link with practice problems
and step-by-step answers. Make sure to check that out if you really want to ace
your exam. Make sure you like this video if you learned something and
subscribe if you want to see more videos just like this one and remember I am
here to show you how to pass Chemistry! So leave a comment below letting me
know what you need help with and I'll see you next time. Grab a pen and paper
Grab a pen and paper and write these practice problems [Laughs] down. [Laughs] Okay.
Grab a pen and paper and try these practice problems
[Laughs]
Grab a pen and paper
and try these practice problems....Straight face