Register to reply

Express the density of a solid substance varying with temperature

Share this thread:
endeavor
#1
Feb23-06, 11:19 PM
P: 176
I need to show that the density of a solid substance varies with temperature as d = d0(1 - 3aT), where a is the thermal coefficient and T is the change in temperature.

I know V = V0 (1 + 3aT) and V = m/d. Since m is constant,

d0 = d(1 + 3aT)
d0 - d03aT = d + d3aT - d03aT
d0(1 - 3aT) = d +3aT(d - d0)

Am I now supposed to assume that the d only changes a little compared to d0, so that (d - d0) = 0?
Phys.Org News Partner Science news on Phys.org
NASA team lays plans to observe new worlds
IHEP in China has ambitions for Higgs factory
Spinach could lead to alternative energy more powerful than Popeye
mukundpa
#2
Feb24-06, 07:21 AM
HW Helper
P: 507
do = d(1 + 3aT)
d = do/(1+3aT) = do(1+3aT)^-1

now expanding using binomial theorem and as a is very small the higher terms can be neglected, gives

d = do(1- 3aT + ....)


MP


Register to reply

Related Discussions
Pretty basic chem/density problem: finding density of irregular shaped soluble solid Chemistry 1
Density of the same substance. General Physics 8
Fruit cell emf varying with temperature Introductory Physics Homework 1
VSM temperature varying tube Engineering Systems & Design 0
Solid with Varying Refractive Index General Physics 2