Which statements about water are true? Choose more than one answer. Water molecules have no subatomic particles
Water does not appear on the periodic table of elements
Water molecules contain a lot of empty space
Molecules of water cannot be broken apart
Hydrogen and oxygen have different properties when separated
Every molecule of water contains two atoms of oxygen

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.