Question

David lifts a book 1.2 meters from the floor to the top of his desk. If the book weighed 0.50 kg, what is the gravitational potential energy gained by the book? Estimate g as 9.81.

Answer 1

Answer:

5.886 J

Explanation:

Given:

The mass of the book is, $m=0.5$ kg

Height of lift is, $\Delta h=1.2$ m

Acceleration due to gravity is, $g=9.81$ m/s²

Now, gain in gravitational potential energy is a function of change in position and is given as:

$\Delta PE=mg\Delta h$

Here, $\Delta PE$ is the change in gravitational potential energy.

Plug in 0.5 kg for $m$, 9.81 for $g$ and 1.2 for $\Delta h$. Solve for $\Delta PE$

$\Delta PE=0.50\times 9.81\times 1.2=5.886\ J$

Therefore, the gain in gravitational energy of the book is 5.886 J.