solve using energy methods

Blocks A and $B$ weigh $5$ lb and $10$ lb $,$ respectively. After striking

block $8,$ block A slides $2$ in $.$ to the right and block $B$ slides $3$ in $.$ to the

righs. The coefficient of kinetic friction between the blocks and the

surface is $=0\mathrm{.}2.$ Find the velocity $v_A$ of block A just before impact if

block $B$ is initially at rest.

Answer: $v_A=5\mathrm{.}054\frac{in}{?}$