The units of density depend on the units used for mass and volume. The most commonly used units are grams per cubic centimetre (g/cm³) or kilograms per cubic metre (kg/m³). These balloons are the same ...

It is tempting to think that some materials are always heavier than other materials. For example, someone might say that metal is heavier than air. But it depends on how much of each material there is ...

Note: This video is designed to help the teacher better understand the lesson and is NOT intended to be shown to students. It includes observations and conclusions that students are meant to make on ...

Introduction Have you ever wondered how a ship made of steel can float? If you drop a steel bolt into a bucket of water, the bolt quickly sinks to the bottom. Then how can a steel ship float? And ...