Answer:
<em>She raised approximately 4 meters as she crosses the bar</em>
Explanation:
<u>Energy Conservation</u>
In the absence of air resistance and any other energy-absorbing events, the total mechanical energy is conserved. Recall the mechanical energy is the sum of the gravitational potential energy and the kinetic energy:
When our athlete is at the ground level her height is 0, thus she has only kinetic energy given by the speed she's at when starting the jump:
Later when she's directly above the bar, she has both energies since some speed remains at a certain height h we must calculate. The mechanical energy is
Equating both energies
Simplifying by m and rearranging
Solving for h
She raised approximately 4 meters as she crosses the bar