Answer
The faucet will rise $2.9~mm$
Work Step by Step
We can find the increase in length of the copper pipe when it is heated:
$\Delta L = \alpha~\Delta T~L$
$\Delta L = (17\times 10^{-6}~K^{-1})(70.0~K)(2.4~m)$
$\Delta L = 2.9\times 10^{-3}~m$
$\Delta L = 2.9~mm$
The faucet will rise $2.9~mm$
