Answer:
V=15.46m/s
Explanation:
By making an energy balance:
Initial energy:  [tex]\frac{K*X^2}{2}[/tex]  where K=1100N/m  and X=4m
Final energy: [tex]\frac{m*V^2}{2} + m*g*h[/tex] Â where m=60kg and h=2.5m
Work done by friction force: -Ff*X Â where Ff = 40N and X=4m
The balance will be:
[tex]\frac{m*V^2}{2} + m*g*h-\frac{K*X^2}{2}=-Ff*X[/tex] Â Solving for V:
[tex]V=\sqrt{\frac{-Ff*X+K*X^2/2-m*g*h}{m/2} }=15.46m/s[/tex] Â using g=9.8m/s^2