Did you complete the reading assignment?
1) Solids maintain form
and shape unless they are stressed.
2) Density depends on both the mass and
volume of an object.
3) Pressure is the force applied to a
Because most of you are familiar with and understand density and pressure in
solids, we will skip over them in the reading quiz. Young's Modulus is a
less well known characteristic of solids. You have actually been exposed to
it earlier in this class through Hooke's law and elastic spring potential;
they are just specific applications of Young's Modulus.
We generally think of solids as matter that maintains its shape and form;
however, some solids can lose there form a lot more easily that others. Young's Modulus basically refers to the deformability of a solid, but not
the breakability of the solid. To understand how these concepts are
different from each other, go to:
and complete the stiffness and strength chart. Note that this is a site from
the UK so biscuit does not have the same definition we use in America, but
instead means any small, hard, grain based product, like a cookie,
dehydrated block of wheat, or cracker, but not a dinner roll.
What has a higher Young's Modulus, a cracker or a nylon rope?
One way to really understand what Young's Modulus actually is, is by
performing the lab on this website. To perform the experiment, press
the 'Next' button under the title of the page and follow the instructions on
the website. Notice though that the website refers to Young's Modulus with
an E instead of a Y.
Is Young's Modulus for a solid dependent upon the geometrical features (like
length and width) of a solid?
In the online lab, you should have found Young's Modulus for steel to be about
2.1 x1011 N/m2. How much force needs to be applied to
a steel wire that is 1 mm thick?
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Was there anything that you didn't understand in the reading assignment?
What was confusing to you?