JEE Advanced Model Paper 1 with solutions for online practice

Two small motors are kept on a smooth table at a separation L. The motors have mass M and 2M and are connected by a light thread. The motors begin to wrap the thread and thereby move closer to each other. The tension in the thread is maintained constant at F. Then the time after which the two motors will collide is √

nML

3F

where n is. (Neglect the dimensions of the motors and their stands).