An object with a mass of 5.0 kg is accelerating toward the surface of earth at a rate of 9.8 m/s^2 which change would double the gravitational force acting between the object and earth? a. doubling the mass of the object b. doubling the height above the surface c. bringing the object to a complete stop d. reducing the rate of acceleration to 4.9 m/s^2

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.