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I'd like to talk to
you about solving

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these kinematics problems.

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So we're going to actually
start by asking ourselves

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three separate
questions anytime we

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start one of these
kinematics problems

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and this will help
us really figure out

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what's happening in the motion.

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So the first question
that we want to ask

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is, how many objects are moving?

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So do we care about more than
one object, and if we do,

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we need to make sure to
label each one distinctively.

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We also want to know how
many dimensions we need

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to care about for each object.

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The second question that
we want to ask ourselves

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is, how many stages of
motion does each object have?

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So for an example,
if you're told

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that a bicycle is
initially accelerating

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and then, at a certain
time, it stops accelerating,

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then you know that that
initial acceleration

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is going to have different
equations of motion

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than the point in
time where it now has

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an acceleration equal to zero.

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The final thing that
we want to think about,

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we want to figure out what
special conditions there are.

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So for example, you might be
told that the cart is initially

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at rest.

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So what does that
mean in reality?

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It means that you can write
down something like, v of 0

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is equal to 0, that's
what it means for the cart

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to initially be at rest.

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v cart is-- v at
time 0 is equal to 0.

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So those are the kinds
of special conditions

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that you need to pay
attention for in the problem

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and that will help
you figure out--

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get all of the numbers
or the variables

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that you need to
solve your equation.

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Once you're done thinking
through these different steps,

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the final thing
you should always

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do before starting a problem
is draw out your problem,

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properly label your
system, and then of course

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draw your origin, your
axes, and your unit vectors.

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And this way, it
will be easy for you

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to organize all of the different
information that you have.