The height of the Washington Monument is measured to be 170 m on a day when its temperature is 35.0°C. What will the change in its height be on a day when its temperature falls to -12.0°C? Although the monument is made of limestone, take the thermal coefficient of expansion to be that of marble.

Question

(answer to be in cm)

Answer 1

To = 9C/5 + 32 = 9*35/5 + 32 = 95oF.
T = 9*(-12)/5 + 32 = 10.4oF.

a max = 7.9*10^-6/oF.

Change = a*(T-To)ho
7.9*10^-6*(10.4-95)*170 = -11.36 cm.
Change = 11.36 cm decrease

Answer 2

Change = coefficient*Length*Difference in Temp
(2.5*10^-6)*170*(-12-35) = -.019975 meters

-.0199m = -1.99cm