The length of a side of a metallic cube at 20° C is 5.0cm. Given that the linear expansively of the metal is 4.0 × 10^-5K^-1, find the volume of the cube at 120° C

darray

9 years ago

Using the formula

L(2) = L(1) [1 + ¥Δt]

The L(1) is the initial length of the cube which is 5cm as given

The ¥ is the linear expansivity = 0.00004 K^-1

Δt is the change in temperature = 120 - 20 = 100*C



L(2) = 5 [1 + (0.00004 x 100)]

= 5 ( 1 + 0.004)

= 5 (1.004)

= 5.02 cm



Since the volume of a cube is given as L^3

The new volume = 5.02^3

= 126.5 cm^3



That's how they arrived at the answer. I think that can help a little bit.

Themmythope1378

2 years ago

Cubic expansivity(√) = 3x Linear expansivity(&)

Where; Linear expansivity(&)= 4.0x10^-5
Cubic expansivity(√)= 3x4.0x10^-5 =1.2x10^-4

Where; Vol. of a cube = L^3
V1=5.0^3=125cm^3

√=(v2-v1)/(v1x ∆ in temp)
1.2x10^-4=(V2-125)/125(120-100)
V2=126.50cm^3.

biogad

9 years ago

please can someone explain dis??