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 first block at this instant is
A. `1/2((Ft^(2))/(2m)+x_(0))`
B. `-1/2((Ft^(2))/(2m)+x_(0))`
C. `1/2((Ft^(2))/(2m)-x_(0))`
D. `(Ft^(2))/(2m)+x_(0)`
