Two objects A and B hang down on either side of a smotth pulley, connected by an inextensible string. The masses of the objects are 3m and km respectivly. A accelerated at 2/5g when released. g=9.8N. What is the value of k. I worked it out to be 1.29, by writing an equation for the tension in the string for both objects. But the the value of k is supposed to be greater than 3. Did I use the wrong method?