The distance from earth to a distant planet is approximately 9 x 107 km. assume that the frame size is 16 kb and the speed of light is 3 108 m/s. assume that the bit rate is 20 mbps.

plot the efficiency versus the distance when the bit rate is set to 20 mbps. discuss this plot.
plot the efficiency versus the bit rate when distance is set to 9 x 107 km. discuss this plot.

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.