Chapter 11, Problem 51A

To determine

Increase in the potential energy of the barbell-earth system.

Answer to Problem 51A

3439.8 J

Explanation of Solution

Given:

Mass of barbell, $m=180\text{ kg}$

Height of barbell, $h=1.95\text{ m}$

Formula used:

  $U=mgh$

Here, U is potential energy, m is mass, g is the acceleration due to gravity and h is height.

Calculation:

Acceleration due to gravity on earth is $g=9.8{\text{ m/s}}^2$ .

The increase in potential energy of the barbell-earth system is

  $\begin{array}{l}\Delta U=mgh\\ =180\times 9.8\times 1.95\\ =3439.8\text{ J}\end{array}$

Conclusion:

So, the potential energy of the book-earth system is 3439.8 J.