Two blocks A and B of masses m1 and m2 connected by uniform string of mass m and length l are placed on smooth floor as shown in the figure. The string also lies on the floor. The block A is pulled by a constant force F.

(a) Find accelerations a of both the blocks and tensions TA and TB at the ends of the string.
(b) Find an expression for tension T in the string at a distance x from the rear block in terms of `T_A`, `T_B` m, l and x.