Density – 14.2, 14.4

About the lecture

In this mini-lecture we explore Topics 14.2 and 14.3 with a discussion of density. In particular, we think about: (i) understanding density using volume and weight; (ii) density = mass/volume, which is often written ρ = m/V; (iii) the density of water: 1 kilogram per litre (ρ = 1 kg/L); (iv) writing density in other units such as grams per litre (g/L), grams per cubic centimetre (g/cm³), and kilogram per cubic metre (kg/m³); (v) how the density of water is always the same no matter how much water you have; (vi) the densities of liquid water, gaseous steam and solid ice, and note that water is a special case where the its solid form (ice) is actually less dense than its liquid form (water); (v) intensive properties, which are those whose values do not change when you change the system size, and extensive properties, which are those whose values do change when you change the system size; and (vi) density as an intensive property, and mass and volume as extensive properties.

About the lecturer

Chris Bell is a Senior Lecturer in the School of Physics at the University of Bristol. His research focuses on the creation and control of novel electronic phases of matter in metals, semiconductors, and insulators. Recently his work has centred on low dimensional systems, including low-density high-mobility two-dimensional superconductors as well as ultrathin ferromagnets.