A 30-year-old woman takes a trip on a rocket, leaving her 20-year-old brother behind. She travels at a speed of 0.8c, and is gone 20 years, according to the younger brother. When she returns, how many years older/younger is she than her brother?
A. 2 years younger
B. 2 years older
C. 3 years older
D. 10 years older
E. 8 years older
Answer: B
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The strongest of evidence that supports the giant impact model for the formation of the Moon is that the
A) Moon has no global magnetic field B) Moon is larger compared to the Earth than other moons C) overall composition of Moon rocks returned from the Apollo program is similar in composition to rocks found on the surface of the Earth D) overall composition of Moon rocks returned from the Apollo program is similar to the composition of Earth's mantle material, except for the lack of volatile elements
A heavy weight is supported by two cables that exert tensions of magnitude
and 
. Which statement is correct?
?
?
a..
b.
c.
d.
e.
We need the mass of the box in order to determine the correct answer.
The region of our solar system between Mercury and Mars has very few asteroids, while the region between Mars and Jupiter has many asteroids
Based on what you have learned, what is the most likely explanation for the lack of asteroids between Mercury and Mars? A) There were very few planetary leftovers in this region, because most of the solid material was accreted by the terrestrial planets as the planets formed. B) It was too hot for asteroids to form in this part of the solar system. C) Gravity was too weak to allow asteroids to form in this part of the solar system. D) All the asteroids that formed between Mercury and Mars later migrated to the asteroid belt between Mars and Jupiter.
What major feature of Saturn's moon Enceladus led scientists to suspect it might have a subsurface ocean?
A) fountains of ice spraying out from the surface into space B) surface lakes of liquid methane or ethane C) its large mass and size D) its many active volcanoes