Consider the following problem: a block of mass m1 is on a frictionless horizontal surface, and connected by a string, through a pulley, to a mass m2 hanging vertically (Figure \(\PageIn...Consider the following problem: a block of mass m1 is on a frictionless horizontal surface, and connected by a string, through a pulley, to a mass m2 hanging vertically (Figure \PageIndex1). (We assume the string is unbreakable, unstretchable, and of negligible mass.) What is the acceleration of the system?