* Surface Area: A tub of water has a much larger surface area than a pot of water. This means there's more contact between the warm water and the ice, allowing for faster heat transfer.

* Volume: The tub of water also has a greater volume, meaning there's more warm water available to absorb the heat from the melting ice.

In essence, the tub of warm water provides a larger reservoir of heat energy to melt the ice more quickly.