Answer:In first case
Explanation:
When two People pull the spring, let the applied force by each person be [tex]F_o[/tex]
and spring constant of spring be k
so Total force is [tex]2F_o[/tex]
total extension according to Hooke's law is
[tex]x=\frac{2F_o}{k}[/tex]
When they detach the spring and apply force in opposite direction then force on either side is F so net extension is
[tex]x'=\frac{F_o}{k}[/tex]
so in first case there will be more extension