In the figure shown if mass of each block is m. Find the acceleration of block A.  (use g=10 m/s2)

Let acc. of block A be aA  and acc. of block B be aB. Hence2T=maA--(1)andmg−4T=maB---(2)Constrained Motion : 2TaA=4TaB∵T∝1a⇒aA=2aBAfter solving we get, from 2×1 and 2​⇒2 2T=maA⇒4T=2maA​                          ⇒mg−4T=maA2​on solving we get ​⇒mg= 5maA2​⇒aA=4ms−2