Physics - NLM Question with Solution | TestHub

Two objects A & B are connected by a light string and these blocks are further connected to block C by thread that passes over a light frictionless pulley as shown. The objects are at rest. At $\mathrm{t}=0$, block B is given a velocity 40 m/s in vertical upward direction. Find the time (in sec) after which string between A & B again becomes tight (string is large, blocks do not collide with each other or with pulley)