Please help if you have the time A string is stretched between fixed supports 2.0 meters apart. When set in transverse vibration at a frequency of 120 Hz the string vibrates in four segments, as shown. What is the wave speed in the string?

Consider a double atwood machine constructed as follows: a mass 4m is suspended from a string that passes over a massless pulley on frictionless bearings. the other end of this string supports a second similar pulley, over which passes a second string supporting a mass of 3m at one end and m at the other. using two suitable generalized coordinates, set up the lagrangian and use the lagrange equations to find the acceleration of the mass 4m when the system is released. explain why the top pulley rotates even though it carries equal weights on each side.