If you as the initial volume to the change in volume, it won't change the results. Because initial volume will get added to both water and copper, so they will cancel each other
V initial +chage in V of water =V initial + change in V of copper
Thus, the initial volume will get cancelled on...
I think you should calculate change in water volume too, use volumetric coefficient as 0.000214/deg C. initial volume of water is same as copper pipe.
From the values we can understand change in volume of water will be much greater compared to copper , also liquid expands more than solid.
If...