Question

Ekaferini Stefandi of Greece won the women's pole vault at the 2016 Games in Rio with a vault height of 4.85 m. We are going to calculate how fast she needed to be going to clear the bar. Assuming energy is conserved. First, we must calculate this from her center of mass which is probably a meter off the ground. So her height was actually 3.85 m. Calculate her speed when she planted her pole for the jump.

Answer 1

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

$\frac{1}{2}mv^2=mgh$

$v=\sqrt{2gh}$

$v=\sqrt{2\times 9.8\times 3.85}$

$v=\sqrt{75.46}$

$v=8.68 m/s$