In this activity, students see that a can of regular cola sinks while a can of diet cola floats. As a demonstration, bubble wrap is taped to the can of regular cola to make it float. This high-volume but light-weight material increases the volume of the object more than it increases the weight. This decreases the density enough for the can-and-bubble wrap object to float. Students will use this idea to make an object that is more dense than water float.