Answer:
that's a hard question for some of us and it sounds like your a teacher but I love that your profile pic is from Tokyo goul I think I spelled it right
Answer:
a. three directions at ~90°
Explanation:
Galena is known for its presence in all types of rocks (igneous, metamorphic and sedimentary rocks). It is predominantly ore of lead which has a chemical configuration of PbS and lead sulfide. Also, newly severed chunks of galena display excellent cleavage in three directions at ninety degrees.
Hence, in this case, the correct answer is "galena’s cleavage is best described as three directions at ~90°"
Answer: get smaller
Explanation:
Parallax is the angle formed by the observation lines to a very distant object from two separated points.
The procedure to measure this distance in the case of a star, is based on observing it from two different places far away from each other, and then through trigonometry reach to the following relationship:
(1)
Where:
is the distance from Earth to the observed star (in Parsecs )
is the earth-sun distance that is equivalent to an astronomical unit (1AU=150000000km)
is the angle of the parallax (in arc seconds )
Now, the distance to an object (measured in parsecs) is the reciprocal of the parallax (measured in arcseconds). Then, in its simplified mode, the stellar parallax is given by the following equation:
(2)
As we can see, there is an inverse relation between the distance and the parallax :
(3)
Hence, if the distance is increased by a factor of 10, the parallax is decreased by a factor of 10.
In other words, the parallax angle gets smaller.
Indirect effects include pluvial lakes, changes in sea level, and isostatic depression.
The answer for this is Tokyo