While preparing for a lab, Genia takes out her contact lenses, puts on eyeglasses, grabs a bag of peanuts in case she gets hungry, changes her shoes in case anything spills, and washes her hands to make sure they are clean. Which part of Genia’s preparation process would most likely cause a problem in the lab? wearing eyeglasses bringing peanuts changing shoes washing hands

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.