About 78% of the air is composed of
a)carbon dioxide.
b)oxygen.
c)nitrogen.
d)argon.
c
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A 5-kg shark swimming at 1 m/s swallows an absent-minded 1-kg fish swimming toward it at 4 m/s. The speed of the shark after his meal is
A) 1/2 m/s. B) 1/5 m/s. C) 1/6 m/s. D) 2/3 m/s. E) 3/2 m/s.
Kepler relied heavily on the telescopic observations of Galileo in developing his laws of planetary motion
Indicate whether the statement is true or false
Which of the following objects are probably not located in the same general region of the solar system in which they originally formed?
A) Kuiper belt comets B) asteroids of the asteroid belt C) Pluto D) Oort cloud comets
Which of the following radionuclides is used to date once-living material?
a. Rubidium-87 b. Potassium-40 c. Thorium-232 d. Carbon-14