Question

two equal masses are connected by a light cord passing over a pulley of negligible mass. at the moment the system is in motion, with the right hand block movingdownward at 1.2 m/s. what is the correct free body diagram?

Answer 1

concept:

when two equal masses are connected by

a light cord passing over a pulley of negligible mass

at the moment the system is in motion,

with the right hand block moving downward at 1.2 m/s

correct free body diagram is

     For Left mass :

       T - mg   = ma

    For right mass :

       mg - T = ma

acceleration : a =( m-m)/(m+m)g    = 0 m/s²

Tension of the cord = T = 2 mm g/(m+m)

                                       = mg