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

5.886 J

Step-by-step 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* 9.81* 1.2=5.886\ J`

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