Chapter 6, Problem 26P

To determine

Change in gravitational potential energy.

Answer to Problem 26P

Solution: $2116.8\text{ J}$

Explanation of Solution

Given:

Mass of pole-vaulter, $m=54\text{ kg}$

Final height, $h_f=4\text{ m}$

Formula Used:

The gravitational potential energy of an object, with mass m , can be calculated by

  $PE=mgh$

Where, g is the gravitational acceleration experienced by the object and h is the height above a certain reference point.

Calculations:

Change in gravitational potential energy is $\Delta PE=P{E}_{final}-P{E}_{initial}$

Where, initial potential energy is zero because pole vaulterwill be at ground level, initial height is zero.

  $\Delta PE=mg{h}_f-0$

Substituting values of $m,g,h_f$

  $\begin{array}{l}\Delta PE=54\times 9.8\times 4\\ \Delta PE=2116.8\text{ J}\end{array}$

Conclusion:Change in gravitational potential energy is $2116.8\text{ J}.$