Answer:8.68 m/s
Explanation:
Given
If the height of vault is h=4.85 m
her center of mass is 1 m above ground
Net height h=3.85 m
conserving energy
Kinetic Energy=gain in Potential Energy
[tex]\frac{1}{2}mv^2=mgh[/tex]
[tex]v=\sqrt{2gh}[/tex]
[tex]v=\sqrt{2\times 9.8\times 3.85}[/tex]
[tex]v=\sqrt{75.46}[/tex]
[tex]v=8.68 m/s[/tex]