The length of a side of a metallic cube at 20ºC is 5.0cm. Given that the linear expansivity of the metal is 4.0 x 10\(^{-5}\)k\(^{-1}\), find the volume of the cube at 120°C.

Chi4sure

2 years ago

Cubic expansivity=3×(4.0×10^-5)
=0.00012

Cubic expansivity¥=V2-V1/Change in temperature

V2=V1(1+¥×change in temperature)

V1= length×breadth×height

Since it's a cube the length,breadth and height are all equal

Therefore V1=5×5×5=125

Change in temperature=120-20=100

V2=125(1+0.00012×100)

V2=126.5

divinemiracle

7 years ago

thanks

dorctob48

6 months ago

let's try it this way too
we need to find a new length first
original length(l)=5.0cm,linear expansivity(¥)=4.0×10^-5,∆T=120-20=100°C=100K from the question
now let's find a new length
L=l(1+¥×∆T)
L=5.0(1+4.0×10^-5×100)
L=5.0(1+4.0×10^-3)
L=5.0×1.004
L=5.02
so our new length (L)=5.02
new volume(V)=L^3
V=5.02^3
V=126.5

chixome

6 months ago

pls correct

Ibrahim fatimoh

9 years ago

But 125cm^3 is not in the question