WEBVTT

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>> This is a short video giving
you some hints on Number 9.

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For Problem 1 of Part A, we are
given the front and top views,

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and we're asked to sketch
the opposite section

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for each of the solids.

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So, for the first one,
here is the top view,

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and here's the front view.

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I didn't complete
the front view.

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Here's the top and
here's the front.

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And we want to clarify
the hidden lines here.

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So we need to do
an offset section,

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so an offset section is one.

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I've got one that
is a cutting plane

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that doesn't go all the
way through; but, instead,

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the position is offset
in order to go

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through the main
features of the solid.

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So here, this is the location of
our offset section here cutting

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in this direction and then
offset so that it goes

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through the center of
this tiny little circle.

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And these arrows indicate the
direction of the line of sight.

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So, in that case, when we create
the corresponding offset section

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in the front, so
we're going to --

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we're going to make
this a solid line here.

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And the two hidden lines
here will become solid also,

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corresponding to the
cylindrical holes.

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One here. And then we
just need to section

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by adding the hatch
line section lines.

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This area here will be
sectioned, sectioned.

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This area here will
also be sectioned.

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This area here is not sectioned

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because the cutting
plane doesn't go

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through the solid part here.

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Similarly, no section
here for the holes.

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Now, for the second part,
Part B of Problem 1 of Part A,

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we're given the front
and top views again.

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This time we want -- it's
asking us to sketch half section

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because the objects here
are -- have symmetry.

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So we don't need to
do a full section.

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So that means, if I choose
to do the cutting section

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on the left side, my cutting
section will only go from here

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to here, and my line of
sight's going this way.

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So my half section
would look something --

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the hidden line here
becomes a solid.

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The hidden line from the
hole becomes a solid.

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And then we're going to
have a solid line here.

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And this is, of course,
the position

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of our [audible] line here.

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I did not keep any of the
hidden lines on the right side.

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That's not sectioned.

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So all I have to do is just
add section lines here,

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section lines here.

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And then add the centerline,
of course, for the circle here

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and for the centerline here.

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And on the right side you don't
show any of the hidden lines.

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Now, for Part B of Lab 9,

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we are given originally
the top and the front.

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And the first part
of it is asking us

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to convert the given front view
into this offset section AA.

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So here's the location
of our offset section.

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And, if we do a cutting
section here along AA

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and show the different
views, you don't need

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to construct a separate
front view.

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You just turn the front view
into the opposite section.

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So this will be hatched
here, hatch, hatch, hatch.

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And for the last
part of Problem B,

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we're asked to find section BB
and show that here to the right.

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In section BB we're supposed
to do a phantom section.

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And note this here.

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This is a phantom section.

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We leave all the hidden
lines the way they are.

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So, in this case, first
construct the right side view,

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a regular right side view.

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And then do not change
any of the hidden lines,

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and simply hatch the arrows that
correspond to solid portions cut

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by your cutting plane BB.

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So it's going to look like this.

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And take note that you need to
use the correct hatch pattern

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for the given material.