The steel would expand by 4. 8 * 10^-3 cm
<h3>How to determine the linear expansion</h3>
The change in length ΔL is proportional to length L. It is dependent on the temperature, substance, and length.
Using the formula:
ΔL= α LΔT
where ΔL is the change in length L = 10cm
ΔT is the change in temperature = 60° - 20° = 40° C
α is the coefficient of linear expansion = 1.2 x 10^-5 °C
Substitute into the formula
ΔL = 
ΔL =
cm
Therefore, the steel would expand by 4. 8 * 10^-3 cm
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