Suppose that there are 10 billion (10,000,000,000,000 ) habitable planets in our galaxy, that 1 in 5 habitable planets has life, that 1 in 1000 planets with life has at some point had an intelligent civilization, and that 1 in 1000 civilizations that
have ever existed is in existence now. How many civilizations would exist at present? A) 200,000
B) 2,000,000
C) 20,000
D) 20,000,000
B
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Heat comes from the Sun to Earth by the process of _______.
a. conduction b. radiation c. convection d. all of these, though radiation is greater
How do humans use their eyes to measure relative distance by parallax?
a. By continuously focusing our eyes on distant objects we can determine distance. b. Since our eyes are separated the brain interprets the relative look angles of these eyes in terms of distance to the object viewed. c. Our eyes can measure the time it takes light to travel from an object and from this we get distance. d. By moving our heads from side to side our brain compares look angles from each of these positions to obtain the distance to the object viewed.
Specific Heat: The water flowing over Niagara Falls drops a distance of 50 m. If all the gravitational potential energy is converted to thermal energy, by what temperature does the water rise? The specific heat of water is 4186 J/kg ? K.
A. 0.10 C° B. 0.12 C° C. 0.37 C° D. 0.42 C°
pH measures
What will be an ideal response?