Question

The Atmospheric Pressure on Mars is $0.61kPa$. What is the pressure in mm$$$$Hg?
$(A)3.2$
$(B)0.63$
$(C)4.6$
$(D)6.3$

Answer 1

At ground level the Martian atmosphere has a pressure of $6.518$ millibars or 0.095 psi as compared to the Earth's sea-level atmospheric pressure of $14.7$ psi. On Mars, the surface pressure varies through the year, but it averages $6$ to $7$ mill bars. That's less than one percent of sea level pressure here. To experience that pressure on Earth, you would need to go to an altitude of about $45$ kilometers ($28$ miles).
To Find:
The pressure in $mmHg$.

Complete step by step answer:
Mars is about half the size of Earth by diameter and has a much thinner atmosphere, with an atmospheric volume less than $1\%$ of Earth's. The atmospheric composition is also significantly different: primarily carbon dioxide-based, while Earth's is rich in nitrogen and oxygen.
In the early days of Mars exploration, the term “sea level” was actually used for Mars, somewhat tongue-in-cheek since there are no seas, referring to the altitude on Mars where the atmospheric pressure was at the triple point of water. That pressure is $612{\text{ }}Pa$, which turns out to be close to an average surface pressure on Mars. For a while, that was used as a reference for a zero altitude, hence “sea level”. However that turned out to be highly variable and uncertain, so the current zero altitude reference has nothing to do with the atmospheric pressure.
Atmospheric pressure on Mars =$0.61kPa$.
$0.61kPa = 0.61kilopascal$
$1kPa = 7.5mmHg$
Therefore, pressure in$0.61kPa$.
$0.61 \times 7.5mmHg$
$= 4.675mmHg$

So, the correct answer is “Option C”.

Note: The atmosphere of Mars is much thinner than earth.
The average surface pressure is only about $610$ pascals $(0.088psi)$ which is less than $1\%$ of the Earth’s value.
Atmospheric pressure on Mars=$0.61kPa$.