hey there it's kaylee are you ready to do some practice problems
we're going to look at a few famous equations and identify the different parts ready let's go
here we have the equation for the area of a triangle if you haven't already mastered
your geometry don't worry we're just going to use this formula to identify the parts
okay so first of all we're going to just look at the right side of the equation
over here and think of this like an expression so how many terms are on the right side
of the equal sign we just learned a term is something that is being added or subtracted
in our expression so how many do we have that's right just one so this is our only term
now within our term how many factors do we have that means how many things are being multiplied
together that's right three things right we have a half we have b and we have h these are all of our
factors now let's take a look at our factors how many do we have 3 that's right
we know that our fraction one-half is a constant value this one right here is a constant
because it's just a number but what about b and h b and h are used here to represent the base
and the height of a triangle now if we take a look at the two triangles we have over here do
you think the base always stays the same in every triangle no way right the base of a triangle can
be different lengths just in these ones here the base in this one is shorter and the base in this
one is longer so b can be varying lengths and how about the height is the height always the same
in every triangle no way right this one's shorter and this one's taller so that means h is also
a varying value now if they're both varying values that means they're both
variables so b and h are both variables and so if we're multiplying our constant value of a half
by two variables in this case what do we call this constant value that's right a coefficient
nice work okay now this one might be a bit more mysterious
this is the formula for the energy of a baseball after it's been thrown by the pitcher
looks a little fancy and not what i usually think of when i see someone throwing a ball
right but again we're just going to look at the right side of the equal sign so over here
too and think of this as an expression now how many terms does this expression have
two right one here and one here and how do we know that because there's two things being
added together they're separated by addition or subtraction
so each of these are our terms and in fact in this formula these two terms are super important this
first term here one half times m times v times v represents the kinetic energy of the baseball
that means how much energy the baseball has due to its movement and the second term is how much
energy the ball has because of gravity now let's look at the first term the kinetic energy term
how many factors are there remember what's a factor things that are being multiplied together
so how many things are being multiplied together in our first term yeah we have a half we have m
we have v and we have v again so what do you think our factors m and v might represent
that's right they're variables but what values do these variables represent the m is used to
represent mass that would mean the mass of the baseball can the mass of a baseball be different
well most baseballs should be about the same mass but this could be the kinetic energy for
any ball so is the mass of uh let's say a beach ball different than the mass of a baseball yeah
definitely right so this mass can be a varying value and that's how we know that it's a variable
now what about v here just so you know these v's are the same there's just two of them
and we multiply something together sometimes we also say v squared since they're the same thing
now these v's represent velocity do you think the velocity of a ball can be different
well i can tell you for sure that this guy probably throws a faster pitch than i do so
yeah the velocity of a ball can be varying and so that means this is also a variable now if these
are both variables and we know that our half here is a constant because it's just a number then what
do we call this half here our constant value being multiplied by variable is called a coefficient
nice work okay so now let's take a look over here at our second term this second term remember is
the energy due to gravity so how many factors are here in our second term our energy due to gravity
remember factor of things being multiplied together so we have m we have g and we have h
so now let's look at our factors m this is the same m over here so when we have a formula or
an equation if we're using the same letter to represent variables then that means those are the
same thing so this is also mass and we've already discovered that mass can be a varying value
why yeah because different balls have different masses so we know that that m is a variable
and now h is another one here h is height and it means how far off the ground
the ball is so do you think that can be a varying value can that change
yeah right if a two-year-old a little guy throws a ball he can only throw it so far
off the ground but this guy's pretty tall so he can throw it higher off the ground
so this can also vary so h is also a variable our height can change now g here is a pretty special
number it's the acceleration due to gravity you don't need to understand what the acceleration
due to gravity means right now but it is important to know that g is a varying value in the universe
so in the entire universe g can be a varying number but on earth g is always the same number
and it's 9.8 meters per second squared so this on earth is a constant so for our purposes of playing
baseball on earth we're going to say that this is not a varying number and it is a constant now for
multiplying a constant acceleration due to gravity on earth by a variable mass and a variable height
then we call g a coefficient but just so you know this number would be different if we were
playing baseball on mars amazing work you are really getting the hang of all these new words
now you're ready to practice on your own have fun and remember to always be
clever