Chapter 11, Problem 38A

To determine

To explain: The energy transformation that takes place when an athlete is pole-vaulting.

Explanation of Solution

Introduction:

Pole-vaulting is an event, in which an athlete runs on a track and jump over the bar, with the aid of a flexible pole. The athlete undergoes various energy transformations during the entire event.

Consider an athlete runs in a track with a flexible pole in hand and then uses the flexible pole to jump over the bar.

This energy transformation associated with the entire event can be differentiate into three distinct phases namely running phase, jumping phase, and free fall phase.

Running Phase:

During running phase, all the energy possessed by the athlete is in the form of kinetic energy.

Jumping Phase:

During jumping phase, the athlete bends the flexible pole to aid the jumping and in this phase some amount of the kinetic energy of the athlete is transferred into the elastic potential energy in the pole.

After some time, the elastic pole straightens and the elastic potential energy stored in the pole gets converted into gravitational potential energy and kinetic energy.

Free Fall Phase:

In this phase, the athlete jumps freely over the bar. When the athlete releases the hand from the pole, some of the gravitational potential energy stored in the pole is converted into the kinetic energy in the athlete. Hence, while falling freely, the athlete contains gravitational potential energy and kinetic energy.

Hence, the athlete possessed by the athlete during the different phases of the pole vaulting event is explained.