Calorimetry And Thermal Expansion - 2

Volume Expansion:-
V₁ : Volume at T₁
V₂ : Volume at T₂       T₂ > T₁

V2 = V1 (1 + )

: Coefficiant of volume expansion.
For i so topic solids

: : = 1 : 2 : 3

As temperature increases density of a solid decreases.
d₂ =
d₂ < d₁
Note: in case of liquid contained in a container, both the liquid as well as conainer expand.
Thermal Stress (Secondary Information):-
When a rod is held between two rigid supports and the temperature is allowed to rise the rigid support prevents the rod from expanding.
This is the cause of stress produced in the rod. thermal expansion (if the rod were free)
l = l
Thermal stress = strain X Y =
= Y
Dum Question:-
Q. A liquid is inside a container. Both are heated what is relative coefficiant of expansion?
A. _r = _e - _c
Q. A Steel glass is filled with a liquid. The coeff. of volume expansion of steel and liquid are same.
Will the liquid overflow.
A. No because y_relative = 0
Q. A sphace of copper is floating in a murcury bath. If the temperature is increased. Sphece will sink deeper or rises? _copper > _mercury.
A. It risel because _relative = _ai - _Hg > 0
Illustration:-
Q. A Surveyor's zom steel tape is correct at a temp. of 20 ⁰C. The distance between two points as measured by this tap on a day when the temp. is 35 ⁰C, is 26 m. What is the true distance between the points?
_steel = 1.2 X 10^-5/ ⁰C
Ans. Let temp. rise above the correct temp. be
= 35 - 20 = 15 ⁰C