NSCI111 Midterm Math Review Problems
Note: The math questions on the test should be relatively easy compared to
- If an object 1 AU in size subtends 1 second of arc in the sky, how distant
is it (in km?) Remember that 60 seconds of arc = 1 minute of arc, 60 minutes
of arc = 1 degree, and 1 AU = 150 million km. Express your answer using
Answer: 3.09x1013 km
Note: This defines the parsec distance unit.
- Phobos orbits Mars at a mean distance of 9378 km, and Deimos orbits Mars
at a mean distance of 23,459 km. If Deimos completes one orbit in 1.262 Earth
days, how long does Phobos take to complete one orbit? In what direction
should the Mars Pathfinder have seen Phobos rise? Why? (One Mars day = 1.08 Earth days.)
Answer: Phobos completes one orbit in 0.319 days, and should have risen
in the West since Phobos moves through the sky faster than Mars rotates.
- Mars has a mass 0.108 times that of Earth. The radius of Mars is
3388 km, and the radius of Earth is 6371 km. If a gallon of water weighs 8.3
lbs. in Houston, how much would that same gallon of water weigh in a
human habitat on Mars?
Answer: 3.2 lbs.