Question

in 2014, amelia quon and her team at nasa set out to build a helicopter capable of flying on mars. because mars’s atmosphere is only one percent as dense as earth’s, the air of mars would not provide enough resistance to the rotating blades of a standard helicopter for the aircraft to stay aloft. for five years, quon’s team tested designs in a lab that mimicked mars’s atmospheric conditions. the craft the team ultimately designed can fly on mars because its blades are longer and rotate faster than those of a helicopter of the same size built for earth.

7 mark for review
according to the text, why would a helicopter built for earth be unable to fly on mars?
a because mars and earth have different atmospheric conditions
b because the blades of helicopters built for earth are too large to work on mars
c because the gravity of mars is much weaker than the gravity of earth
d because helicopters built for earth are too small to handle the conditions on mars

Explanation:

The text states that Mars' atmosphere is only 1% as dense as Earth's, so a standard (Earth - built) helicopter wouldn't get enough resistance to its rotating blades to stay aloft. This means the different atmospheric conditions (density) between Mars and Earth prevent an Earth - built helicopter from flying on Mars. Option A says this, while B (blade size for Earth - built not about being too large), C (gravity not mentioned as the reason), and D (Earth - built helicopters' size not the issue, it's atmospheric resistance) are incorrect.

Answer:

A. Because Mars and Earth have different atmospheric conditions