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.
Another common standard classical quartet is the piano quartet, consisting of violin, viola, cello, and piano. Romantic composers Beethoven, Brahms, and Mendelssohn each wrote three important compositions in this form, and Mozart, DvoÅÃ¡k, and Gabriel FaurÃ© each wrote two.