Answer:
1) [tex]v_{A} \approx 8.272\,\frac{m}{s}[/tex]
Explanation:
1) Let assume that the campion begins running at a height of zero. The movement of the Olympic champion is modelled after the Principle of Energy Conservation:
[tex]K_{A} = K_{B} + U_{g,B}[/tex]
[tex]\frac{1}{2}\cdot m \cdot v_{A}^{2} = \frac{1}{2}\cdot m \cdot v_{B}^{2} + m \cdot g \cdot h_{B}[/tex]
[tex]\frac{1}{2} \cdot v_{A}^{2} = \frac{1}{2} \cdot v_{B}^{2} + g \cdot h_{B}[/tex]
The minimum speed is obtained herein:
[tex]v_{A}=\sqrt{v_{B}^{2} + 2 \cdot g \cdot h}[/tex]
[tex]v_{A} = \sqrt{(6.7\,\frac{m}{s} )^{2}+2\cdot (9.807\,\frac{m}{s^{2}} )\cdot (1.2\,m)}[/tex]
[tex]v_{A} \approx 8.272\,\frac{m}{s}[/tex]
The minimum speed he need at launch point is [tex]8.27m/s[/tex]
Energy is neither be created nor be destroyed just change into one form to another form.
[tex]\frac{1}{2}mv^{2} =\frac{1}{2}mv_{a}^{2} +mgh\\ \\v=\sqrt{v_{a}^{2}+2gh }[/tex]
Where,
Given that, [tex]v_{a}=6.7m/s,h=1.2m,g=9.8m/s^{2}[/tex]
Substitute all values in above relation.
[tex]v=\sqrt{(6.7)^{2}+2*9.8*1.2 } \\\\v=\sqrt{68.41}=8.27m/s[/tex]
Learn more about the center of mass here:
https://brainly.com/question/874205
