Some objects float in water and other sink. But did you know that you can change whether something floats or sinks by adding a substance to the water? Let's try it and see! Pour water into a cup until ...

If the upthrust is less than the weight of the object, the object will sink. If the density of the ... and there is zero resultant force, so you float at that level.

They're floating away. Floating away? But how? Did you ever wonder why hot air balloons float? You may already have some ideas. Think about them and then choose one of the options below that seems ...