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 quartet was developed into its current form by the Austrian composer Joseph Haydn, with his works in the 1750s establishing the genre. Ever since Haydn's day the string quartet has been considered a prestigious form and represents one of the true tests of the composer's art. With four parts to play with, a composer working in anything like the classical key system has enough lines to fashion a full argument, but none to spare for padding.