According to optimistic estimates, the end of habitability of Earth will come about
A) a few hundred thousand years from now
B) a billion years from now
C) 3 to 4 billion years from now
D) 100 million years from now
C
You might also like to view...
About how many extrasolar planets have been discovered (as of 2008)?
A) tens B) hundreds C) thousands D) tens of thousands
A person applies a constant force of 20 N to a rock of mass 1000 kg, for a total of 20 seconds. What is the work done by this person if the rock does not move at all by this applied force?
A) 1000 J B) 2000 J C) 20,000 J D) 0 J E) 400 J
You are driving along a highway at 35.0 m/s when you hear the siren of a police car approaching you from behind at constant speed and you perceive the frequency as
You are relieved that he is in pursuit of a different driver when he continues past you, but now you perceive the frequency as What is the speed of the police car? The speed of sound in air is A) 40.1 m/s B) 41.7 m/s C) 39.2 m/s D) 30 m/s E) 38.4 m/s
End A of a Slinky is held motionless near the ceiling. End B is held on the floor so that there is a slight stretch. End B is quickly rotated one half turn about the axis of the Slinky and then returned to its original position, so as to "twist" and then "untwist" the coils. The wave so produced is a
A. transverse wave. B. standing wave. C. longitudinal wave. D. None of these choices are correct