Which of the following observations led bohr to formulate his model of the hydrogen atom? which of the following observations led bohr to formulate his model of the hydrogen atom? neutrons form a diffraction pattern when scattered from a nickel crystal. the peak of blackbody radiation moves to shorter wavelengths as temperature increases. a low-density gas emits a series of sharp spectral lines. electrons are observed to have wave nature.

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.