What did ancient civilizations achieve in astronomy?
a. predicting eclipses
b. time keeping
c. monitoring lunar cycles
d. predicting seasons of agriculture
e. all of the above
e. all of the above
You might also like to view...
Glaucoma occurs because
a. the eye cannot accommodate properly. b. the shape or size of the eye is not normal. c. there is too much pressure in the fluid in the eyeball. d. the lens is partially or totally opaque.
Algol consists of a 3.7 MSun main-sequence star and a 0.8 MSun subgiant. Why does this seem surprising, at least at first?
A) A star with a mass of 3.7 MSun is too big to be a main sequence star. B) The two stars should be the same age, so we'd expect the subgiant to be more massive than the main-sequence star. C) It doesn't make sense to find a subgiant in a binary star system. D) The two stars in a binary system should both be at the same stage of life; that is, they should either both be main sequence stars or both be subgiants.
The figure shows a distance vs. time graph of an object with three distinct regions, I, II, and III
?
The object’s speed is greatest in region I.
a.
True
b.
False
A train starts from rest and accelerates uniformly until it has traveled 5.6 km and acquired a forward velocity of The train then moves at a constant velocity of for 420 s. The train then slows down uniformly at until it is brought to a halt
The acceleration during the first 5.6 km of travel is closest to which of the following? A) 0.16 m/s^2 B) 0.14 m/ s^2 C) 0.17 m/ s^2 D) 0.19 m/ s^2 E) 0.20 m/ s^2