Tripling the focal length of a telephoto lens, while holding aperture size constant, will change the light intensity admitted to the film by what factor?
a. 0.11
b. 0.33
c. 3.0
d. 9.0
e. 0.50
a
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In a steam engine, steam at 140°C in a turbine does work on an external system, and the steam leaves the turbine at 100°C. The efficiency of the steam engine is 5%. The relevant physical principle is the first law of thermodynamics
a. True b. False Indicate whether the statement is true or false
Graphical Analysis: The figure shows a graph of the position of a moving object as a function of time.(a) What is the average velocity of the object from t = 0 s to t = 4.0 s?(b) What is the average velocity of the object from t = 0 s to t = 6.0 s?
Fill in the blank(s) with the appropriate word(s).
Which of the following provides direct evidence that the chemical building blocks of life (such as amino acids and DNA bases) could have formed naturally under the conditions that were present on the early Earth?
A) Fossil remains of life date to fairly early in Earth's history. B) These chemicals have been formed in laboratory experiments that recreate conditions of the early Earth. C) DNA studies show that all known life on Earth evolved from a common ancestor. D) We have found evidence of complex carbon molecules on Saturn's moon Titan.
Among the points and circles shown on this diagram, which one(s) have varying right ascension?
A) the celestial equator and the ecliptic B) Earth's equator and the celestial equator C) only the celestial equator D) the north and south celestial poles