Question

Part of a steel tape used by a surveyor is 20m at 12°c.what is the overall length measured by using this part of the tape one hundred times on a warmer day corresponding to 22°c(linear expansivity of steel =1.1×10^-5k-1

Answer 1

$$\Delta l=l_0\alpha\Delta T$$

$$\Delta l={\rm 20\:m*1.1*10^{-5}\: K^{-1}*10\: K}\\ =2.2*10^{-3}\:\rm m$$