Answered

Several planets in the solar system have different gravitational accelerations. If air resistance is ignored, on which planet would a space probe with a mass of 250 kg have the highest speed after falling 25 m?

\begin{tabular}{|l|l|l|}
\hline
Planet & Mass, [tex]$10^{24}~kg$[/tex] & \begin{tabular}{l}
Acceleration due to gravity, \\
[tex]$m/s^2$[/tex]
\end{tabular} \\
\hline
Venus & 4.87 & 8.9 \\
\hline
Earth & 5.97 & 9.8 \\
\hline
Uranus & 86.8 & 8.7 \\
\hline
Saturn & 568 & 9 \\
\hline
\end{tabular}



Answer :

To determine on which planet a space probe of mass 250 kg falling from a height of 25 meters would achieve the highest final speed, we can apply the principles of physics related to free fall. Ignoring air resistance, the final speed [tex]\(v\)[/tex] of the probe can be calculated using the kinematic equation, which derives from the conservation of mechanical energy:

[tex]\[ v = \sqrt{2 \cdot g \cdot d} \][/tex]

where:
- [tex]\( g \)[/tex] is the acceleration due to gravity on the planet.
- [tex]\( d \)[/tex] is the distance fallen (25 meters in this case).

Let's go through the calculation of the final speed for each planet one by one using the given acceleration due to gravity values:

### 1. Venus
[tex]\( g_{Venus} = 8.9 \, m/s^2 \)[/tex]

[tex]\[ v = \sqrt{2 \cdot 8.9 \cdot 25} \][/tex]

The calculated speed is approximately [tex]\( 21.10 \, m/s \)[/tex].

### 2. Earth
[tex]\( g_{Earth} = 9.8 \, m/s^2 \)[/tex]

[tex]\[ v = \sqrt{2 \cdot 9.8 \cdot 25} \][/tex]

The calculated speed is approximately [tex]\( 22.14 \, m/s \)[/tex].

### 3. Uranus
[tex]\( g_{Uranus} = 8.7 \, m/s^2 \)[/tex]

[tex]\[ v = \sqrt{2 \cdot 8.7 \cdot 25} \][/tex]

The calculated speed is approximately [tex]\( 20.86 \, m/s \)[/tex].

### 4. Saturn
[tex]\( g_{Saturn} = 9.0 \, m/s^2 \)[/tex]

[tex]\[ v = \sqrt{2 \cdot 9.0 \cdot 25} \][/tex]

The calculated speed is approximately [tex]\( 21.21 \, m/s \)[/tex].

### Comparison of Speeds
To find the maximum speed, we compare the final speeds calculated for each planet:
- Venus: [tex]\( 21.10 \, m/s \)[/tex]
- Earth: [tex]\( 22.14 \, m/s \)[/tex]
- Uranus: [tex]\( 20.86 \, m/s \)[/tex]
- Saturn: [tex]\( 21.21 \, m/s \)[/tex]

The highest speed attained is [tex]\( 22.14 \, m/s \)[/tex] on Earth.

### Conclusion
Thus, the space probe would have the highest speed after falling 25 meters on Earth, reaching approximately [tex]\( 22.14 \, m/s \)[/tex].