Answer:
Explanation:
Given
mass of Pole-vaulter [tex]m=61.8 kg[/tex]
height attained [tex]h=4.1 m[/tex]
(a)Speed at which she lands will be given by conserving Energy
i.e. [tex]mgh=\frac{1}{2}mv^2[/tex]
[tex]v=\sqrt{2gh}[/tex]
[tex]v=\sqrt{2\times 9.8\times 4.1}[/tex]
[tex]v=8.96 m/s[/tex]
(b)she stops in t=0.6 s
[tex]F_{avg}[/tex] is given by change in momentum in given time
[tex]F_{avg}=\frac{\Delta P}{\Delta t}[/tex]
[tex]F_{avg}=\frac{61.8\times 8.96}{0.6}[/tex]
[tex]F_{avg}=922.88 N[/tex]
