Which statement about extrasolar planets found to date is true?
A) All are terrestrials, comparable in size to Earth.
B) All lie more than 2 AU from their star.
C) Most have orbital periods of more than a year.
D) Some are so close to their stars that their periods are just a few days.
E) Few are found by Doppler shifts of their stars, due to their gravity.
D
You might also like to view...
A 8.0-?F uncharged capacitor is connected in series with a 6.0-k? resistor, an ideal 20-V dc source, and an open switch. If the switch is closed at time t = 0.0 s, what is the charge on the capacitor at t = 9.0 ms?
A) 0 C B) 37% of the minimum charge C) 68% of the minimum charge D) 96% of the maximum charge E) 17% of the maximum charge
The value of an object's acceleration may be characterized in equivalent words by which of the following?
a. displacement b. rate of change of displacement c. velocity d. rate of change of velocity
People settle on floodplains because
A) the chance of flooding is very rare. B) floodplain soil is nutrient rich and good for agriculture. C) of river access. D) river access and rich soils.
According to this graph, the minimum size of an object that could cause a mass extinction is a little less than _____.
A. 10 m B. 100 m C. 1 km D. 10 km E. 100 km