Coefficient on Linear Expansion Flashcards
Equipment needed for the experiment
Coeffiecient of Linear ExpansionApparatus
Electric Stove
Meterstick
Thermometer
Steam Generator
Beaker
Rubber Tube
Most materials expand somewhat when heated through a ____ that does not produce
a change in phase.
temperature range
increases the average amplitude of vibration of the atoms in the
material which increases the average separation between the atoms.
heat
formula for change in L (length)
ΔL = αL Δt
in the formula, ΔL = αL Δt
α is
coefficient of linear expansion for the material
in the formula, ΔL = αL Δt
Δt is?
temperature change
linear thermal expansion formula
ΔL = αL Δt;
example of materials that are not isotropic
asymmetric crystal
its α can have different value depending on the axis along which
the expansion is measured.
non-isotropic material
α can have a different value depending on the ___ along which
the expansion is measured
axis
α can also vary somewhat with temperature so thatthe degree of expansion
depends not only on the magnitude of the temperature change, but on the ___temperature as
well
absolute
what α is measured in the experiment
copper
aluminum
brass
formula of length of change in the experiment
ΔL=(FR-IR)(a/b)
experimental value of coefficient of linear expansion of metal equation
α = ∆L/Lo∆t
refers to the phenomenon where the dimensions of materials change as a
result of temperature variations
thermal expansion
Most substances ____when heated and ___when cooled.
expand
contract
, refers to the change in one dimension (length) of a solid object.
linear expansion
is a material-specific value that quantifies how much a
material’s length changes with a change in temperature.
e coefficient of linear expansion
coefficient of linear expansion is denoted by what greek symbol
α
defined as the fractional change in
length per degree of temperature change:
coefficient of linear expansion
Expansion joints are placed between sections of ___ tracks to prevent buckling during hot weather.
what real-word application
rail way tracks
Expansion joints are also used in ____to allow for thermal expansion and
contraction of the materials.
what real world example
bridges
Bimetallic strips, which consist of two metals with different coefficients of
expansion, are commonly used in temperature control devices.
what real world example
thermostats
factors affecting linear expansion (3)
Material
Temperature Change
Initial length
Different materials have same coefficients of linear expansion
T/F
False
which expands more, metal or ceramics/glass?
metal
: A larger temperature difference causes a greater expansion
T/F
True
Longer objects will experience more significant changes in length.
T/F
True
aluminum road has an initial length of 50 cm at room temp of 25 degrees celsius
after heating, the final length is 50.05 cm and the water temp is 100 degrees celsius
find a
1.33x10^-5 per oC
