When a pole vaulter reaches the top of her vault, she is at her maximum height. At this point, her speed is momentarily zero, which means her kinetic energy is zero. However, she has converted her kinetic energy (from her run-up and the vault) into potential energy at the peak height of the vault.
Given this information, the correct answer is:
a) The kinetic energy is less than the potential energy.
At the peak, all of her kinetic energy has been transformed into potential energy, so while her potential energy is at a maximum, her kinetic energy is effectively zero.
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