The table below shows the acceleration of gravity on different bodies in the solar system.

\begin{tabular}{|c|c|}
\hline
Object & \begin{tabular}{c}
Acceleration of gravity \\
[tex]$\left( m / s^2 \right)$[/tex]
\end{tabular} \\
\hline
Earth & 9.8 \\
Mercury & 3.59 \\
Mars & 3.7 \\
Neptune & 14.07 \\
Uranus & 9.0 \\
Pluto & 0.42 \\
\hline
\end{tabular}

On which body would a [tex]$100 \text{ kg}$[/tex] man have the least gravitational potential energy when lifted to a height of [tex]$3 \text{ m}$[/tex]?

A. Neptune
B. Pluto
C. Earth
D. Mercury



Answer :

To determine on which body the gravitational potential energy (GPE) is the least for a [tex]\(100 \text{ kg}\)[/tex] mass lifted to a height of [tex]\(3 \text{ m}\)[/tex], we can use the formula for gravitational potential energy:

[tex]\[ \text{GPE} = m \cdot g \cdot h \][/tex]

where:
- [tex]\( m \)[/tex] is the mass in kilograms (kg),
- [tex]\( g \)[/tex] is the acceleration due to gravity in meters per second squared ([tex]\( m/s^2 \)[/tex]),
- [tex]\( h \)[/tex] is the height in meters (m).

We need to calculate the GPE for each of the given bodies.

1. Earth:
- Acceleration due to gravity, [tex]\( g = 9.8 \, m/s^2 \)[/tex]
- Mass, [tex]\( m = 100 \, kg \)[/tex]
- Height, [tex]\( h = 3 \, m \)[/tex]
- Gravitational Potential Energy, [tex]\( \text{GPE} = 100 \times 9.8 \times 3 = 2940 \, J \)[/tex]

2. Mercury:
- Acceleration due to gravity, [tex]\( g = 3.59 \, m/s^2 \)[/tex]
- Mass, [tex]\( m = 100 \, kg \)[/tex]
- Height, [tex]\( h = 3 \, m \)[/tex]
- Gravitational Potential Energy, [tex]\( \text{GPE} = 100 \times 3.59 \times 3 = 1077 \, J \)[/tex]

3. Neptune:
- Acceleration due to gravity, [tex]\( g = 14.07 \, m/s^2 \)[/tex]
- Mass, [tex]\( m = 100 \, kg \)[/tex]
- Height, [tex]\( h = 3 \, m \)[/tex]
- Gravitational Potential Energy, [tex]\( \text{GPE} = 100 \times 14.07 \times 3 = 4221 \, J \)[/tex]

4. Pluto:
- Acceleration due to gravity, [tex]\( g = 0.42 \, m/s^2 \)[/tex]
- Mass, [tex]\( m = 100 \, kg \)[/tex]
- Height, [tex]\( h = 3 \, m \)[/tex]
- Gravitational Potential Energy, [tex]\( \text{GPE} = 100 \times 0.42 \times 3 = 126 \, J \)[/tex]

Comparing the gravitational potential energies:

- Earth: [tex]\( 2940 \, J \)[/tex]
- Mercury: [tex]\( 1077 \, J \)[/tex]
- Neptune: [tex]\( 4221 \, J \)[/tex]
- Pluto: [tex]\( 126 \, J \)[/tex]

The body on which a [tex]\(100 \text{ kg}\)[/tex] man has the least gravitational potential energy when lifted to a height of [tex]\(3 \text{ m}\)[/tex] is Pluto.

Therefore, the answer is:
B. Pluto