Answer:
1. Galileo.
2. Newton.
3. Kepler.
4. Brahe.
5. Refracting telescope.
6. Reflecting telescope.
7. Astrolabe
8. Camera.
9. Radio telescope.
Explanation:
1. Galileo: he discovered details of a lunar surface.
2. Newton: he invented first reflecting telescope.
3. Kepler: he found planets had elliptical orbits.
4. Brahe: he performed a systematic mapping of sky.
5. Refracting telescope: uses a large glass lens.
6. Reflecting telescope: uses a mirror to focus light.
7. Astrolabe: tool used to determine location of a star.
8. Camera: instrument that accumulates light from an object to show more detail.
9. Radio telescope: records sounds of stars.
Answer:
V ≈ 4577.204 cm^3
Explanation:
Use the volume formula V=4/3πr^3 to find the volume. Since you need the radius but are given the diameter, divide it by 2 to get half.
21.4/2 = 10.7
Now plug that into the formula and solve:
V=4/3πr^3
V=4/3π(10.7)^3
V= 4/3π(1,092.7272)
V= 4/3 * 3432.903
V= 4 * 3432.903/3
V = 13731.614/ 3
V ≈ 4577.204 cm^3 or whatever unit is stated.
Answer:
Afghanistan's mountains have kept the country from ever being invaded.
Explanation:
Afghanistan is a country in terrible conditions, and this is not the case just nowadays but it has been like that for a very long time. Despite all of the internal troubles of the country and it seems to be very weak in pretty much every sector, it has never been invaded in the past few centuries, and very rarely in the more distant history and always it has been short-lasting.
The main reason for this has been the mountains and the general geography of the country. Very high and rugged mountains are separating the country from potential invaders. Even if an invading force manages to go through the mountains, it will suffer great losses just by doing so, and what comes next is desert and more rugged terrain, which will further damage them, so by the time they engage in battle, they will be too weak to conquer Afghanistan.