A particle of positive charge q and mass m enters with velocity `Vhati` at the origin in a magnetic field `B(-hatk)` which is present in the whole space. The charge makes a perfectely inelastic collision with an identical particle (having same charge) ar rest but free to move at its maximum positive y-coordinate. After collision, the combined charge will move on trajectory where `r=(mV)/(qB)`.
A. `y = (mv)/(qB) (- hat(i))`
B. `(x + r)^(2)+(y - r//2)^(2) = r^(2)//4`
C. `(x-r)^(2) +(y-r)^(2) =r^(2)`
D. `(x-r)^(2)+(y+r//2)^(2) =r^(2)//4`
