#### Thermal Stress

Steel railroad rails are laid in sections, each L = 10 m long. Assume that
they are
laid at a temperature of 20°C with a gap between adjacent sections
of g = 3 mm.
- By how many millimeters can each section get longer before adjacent
sections (excluding the two end sections) touch ?

- At what temperature would adjacent sections touch ?

- By how many degrees could the temperature increase further before
the thermal stress in the rails reaches 200 MPa (=stress limit for steel) ?

Assume : Coefficient of thermal expansion α=12.0*10^{-6} m/(m °C) and Young's modulus E = 200 GPa