Question

A submerged can of Coke sink, but a can of Diet Coke will float. (Try it!) Explain.

Short answer

The density of Coke is greater than the density of the Diet Coke.

Step-by-step solution

Understanding the concept of buoyant force (upthrust)

The buoyant force or upthrust is the force preventing the motion of a body in a liquid. This force makes the motion of the body difficult inside a liquid. In other words, it slows down or prevents the sinking process.

The density of a body determines whether it sinks or floats in a liquid.

Analysis of the situation and conclusion.

The normal (or regular) Coke has natural sugar as its ingredient. On the other hand, the Diet Coke contains artificial sugar. Artificial sugar is needed in very little quantity to get the same level of sweetness as normal Coke.

The difference in the quantity of these two sugars in both Cokes causes a change in their densities. Hence, the Diet Coke has a lower density than normal Coke. So, the can of normal Coke will sink, but a Diet Coke will float.