In free space, a particle $A$ of charge $1 \mu \mathrm { C }$ is held fixed at point $P$. Another particle $B$ of the same charge and mass $4 \mu \mathrm {~g}$ is kept at a distance of 1 mm from $P$. If $B$ is released, then its velocity at a distance of 9 mm from $P$ is:\\
[Take $\frac { 1 } { 4 \pi \epsilon _ { 0 } } = 9 \times 10 ^ { 9 } \mathrm {~N} \mathrm {~m} ^ { 2 } \mathrm { C } ^ { - 2 }$ ]\\
(1) $1.0 \mathrm {~m} \mathrm {~s} ^ { - 1 }$\\
(2) $1.5 \times 10 ^ { 2 } \mathrm {~m} \mathrm {~s} ^ { - 1 }$\\
(3) $2.0 \times 10 ^ { 3 } \mathrm {~m} \mathrm {~s} ^ { - 1 }$\\
(4) $3.0 \times 10 ^ { 4 } \mathrm {~m} \mathrm {~s} ^ { - 1 }$