Which of the following statements about Newton's Third Law is the most true? a
The forces acting upon two objects are dependent on the initial velocities of the objects
b
The law of conservation of momentum is obeyed in all systems
c
The two objects colliding will have a change in their masses, but not necessarily their velocities
d
The forces acting on two colliding objects are equal, but the effects of those forces on those objects may not be equal

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.