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.
The string instrument family is perhaps the section of the orchestra that offers the greatest range of expression, intensity, and nuance. It is in essence the foundation of the orchestra. The reason is the number of different instruments that belong to the family. On one side of the family are the bowed instruments like the violin, which require that the strings be played by a bow. On the other end are the instruments that are plucked such as the guitar, the harp, and even the piano.