Plz solve this by work energy and using second law

$2)$ The blocks shown are connected by an inextensible cable. The coefficient of friction between the $\backslash (10-\backslash$mathrm$\{$lb$\}\backslash )$ block$($A$)$ and the floor is $0\mathrm{.}6.$ If the blocks are released from rest when the spring is stretched $15$ inches, find: a$)$ maximum velocity of the blocks, b$)$ stretch in the spring at maximum velocity. Block $\backslash ($ B $\backslash )$ weighs $2-$lb$.$

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