The captain of a spaceship orbiting planet X discovers that to remain in orbit at from the planet's center, she needs to maintain a speed of What is the mass of planet X? (G = 6.67 10-11 N m2/kg2 )
A) 2.8 1019 kg
B) 4.2 1017 kg
C) 2.8 1016 kg
D) 4.2 1014 kg
Question 2
An atom's atomic number is
A) the number of protons in its nucleus.
B) the number of electrons orbiting the nucleus of the neutral atom.
C) Both of the above.
D) the number of electrons orbiting the nucleus of the ionized atom.
E) All of the above.
Extent of agricultural activity across the planet (data from Foley et al. 2005).
Uranus's aurorae against its equatorial rings, imaged by the Hubble telescope. Unlike the auror
Image of an Almost-Extrasolar Planet
Dwarf Planet Eris
The skulls of living haplorhines differ from those of strepsirhines by having large brains, an enclo
Human of the planet's net primary production and appropriation of NPP