Two blocks of equal mass `m` are connected by an unstretched spring and the system is kept at rest on a frictionless horizontal surface. A constant force `F` is applied on the first block pulling away from the other as shown in Fig.
If the extension of the spring is `x_(0)` at time `t`, then the displacement of the second block at this instant is
A. `((Ft^(2))/(2m) - x_(0))`
B. `(1)/(2) ((Ft^(2))/(2m) + x_(0))`
C. `(1)/(2)((2Ft^(2))/(m) - x_(0))`
D. `(1)/(2)((Ft^(2))/(2m) - x_(0))`
