Aperson is trying to judge whether a picture (mass = 1.05 kg) is properly positioned by temporarily pressing it against a wall. the pressing force is perpendicular to the wall. the coefficient of static friction between the picture and the wall is 0.720. what is the minimum amount of pressing force that must be used?

The two required components for a generator are

An automobile steering wheel is shown. what is the ideal mechanical advantage? if the ama is 8, what is the efficiency of the steering wheel?

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.