All the following statements are true. Which one makes it possible to learn of the existence of extrasolar planets without seeing the planets themselves?
A) Planets exert gravitational tugs on their stars that cause stars to orbit around the center of mass of their planetary systems.
B) Planets reflect visible light from their stars.
C) Planets emit infrared light.
D) All the planets in a planetary system tend to orbit their star in the same direction and approximately the same plane.
A) Planets exert gravitational tugs on their stars that cause stars to orbit around the center of mass of their planetary systems.
You might also like to view...
Friction: Jason takes off across level water on his jet-powered skis. The combined mass of Jason and his skis is 75 kg (the mass of the fuel is negligible). The skis produce a forward thrust of 200 N and have a coefficient of kinetic friction with water of 0.10. Unfortunately, the skis run out of fuel after only 90 s. What is Jason's top speed?
A. 150 m/s B. 240 m/s C. 24 m/s D. 90 m/s
Compare two diverging lenses similar except that lens B is rated at 20 Diopters, whereas lens A is rated at 10 Diopters. The focal length of lens B is
A) twice the focal length of lens A. B) one-fourth of the focal length of lens A. C) one-half of the focal length of lens A. D) 1/ of the focal length of lens A. E) four times the focal length of lens A.
Ron is standing near a railroad track. A train is moving toward him at 60 mph, and it blows its horn. What will Ron notice as the train moves past him?
A) As the train moves away, the frequency of the horn will be higher than when the train comes closer. B) As the train approaches, the horn will sound higher in pitch than when the train moves away. C) The horn will produce a multiple echo effect as the train moves closer to Ron. D) There will be no change in the pitch of the horn as the train moves past Ron.
The significance of a Carnot engine is that
A. all automobiles operate on the Carnot cycle B. it has the maximum possible efficiency of any engine operating between the same two temperatures C. it violates the second law of thermodynamics D. it violates the first law of thermodynamics