Question

How large an expansion gap should be left between steel railroad rails if they may reach a maximum temperature 32.0°C greater than when they were laid? Their original length is 27.0 m.

Answer 1

Solution:

Given:

L_o = 27 m

∆T = 32.0°C

The gap between the steel rails is given by the formula:

∆L = L_o ∆T

Since: the coefficient of linear expansion for steel is: = 12 x 10⁻⁶ /°C.

Therefore: Expansion gap (∆L) = (27 m)(12 x 10⁻⁶ /°C)(32.0°C) = 0.010368 m = 1.0368 cm.

Therefore: an expansion gap of 0.010368 m or 1.0368 cm should be left between steel railroad rails if they may reach a maximum temperature 32.0°C greater than when they were laid