Whilst it’s still cold working from home, I’ll often use a hot water bottle to keep warm. I’m often curious if it’s better to fill it more or less and whether it makes any difference to the bottle staying warm. In consistent and matching conditions, would it make any difference how much water was put in the bottle, and why?
In: Chemistry
There’s another aspect not yet discussed, the shape of the vessel. a sphere has the highest possible ratio of volume to surface area. all other shapes have lower ratios.
As you fill a water bottle it bulges, making its shape closer to spherical, meaning the ratio of volume to surface area reduces, so its heat retention improves.
Latest Answers