Pressure is force over area. So assuming your cube is at rest and on earth, then the force is mass x gravity and the pressure is mass x gravity / area.
A string quartet is made up of four musicians playing two violins, a viola, and a cello. These are all string instruments played either by plucking the strings or using a bow. The violins are the smallest and typically play the higher notes. The viola and cello are larger instruments and play the lower notes.
In classical music, trios or quartets either blend the sounds of musical instrument families (such as piano, strings, and wind instruments) or group together instruments from the same instrument family, such as string ensembles or wind ensembles.