In water, a can of diet coke floats while a can of regular coke sinks.

The artificial sweetener in diet diet coke is hundred of times sweeter per unit volume than regular sugar, However, sugar in regular coke is denser, which makes it sink. Regular coke contains almost 11 teaspoons of sugar per can. On an average, Americans ingest 10.8 pounds of sugar per person from drinking coca-cola alone. Floating occurs because floating objects displace, or push aside, a certain amount of liquid. If an object displaces more than its weight in liquid, it floats; otherwise it sinks. Some other facts about coke are:
1. If every drop of coke ever produced were put into 8 ounce bottles and laud end to end, they'd reach moon and back over 2000 times. 
2. Coca cola spends more money on advertising than Microsoft and Apple.
3. The average Mexican drinks more coke than average American, British, Indian and Chinese combined.