A slab of concrete and an insulating board are in thermal contact with each other. The temperatures of their outer surfaces are 68°F and 50°F. Determine the rate of heat transfer (in BTU/ft2/h) if the R values are 1.93 and 8.7 ft2/°F/h/BTU, respectively
a. 9.7
b. 2.5
c. 5.3
d. 1.7
e. 28
d
Physics & Space Science
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A glass block, for which n = 1.52, has a blemish located 3.3 cm from one surface. At what distance from that surface does the image of the blemish appear to the outside observer?
a. 5.0 cm b. 2.2 cm c. 4.1 cm d. 2.7 cm e. 3.3 cm
Physics & Space Science
Aside from Earth, Venus is the most likely place for life to exist in the Solar System
a. True b. False Indicate whether the statement is true or false
Physics & Space Science
Kepler's second law of planetary motion is known as the law of
a. ellipses. b. equal areas. c. harmonic periods. d. gravitation.
Physics & Space Science
Astronomers estimate that new stars form in our galaxy at the rate of about
A) one per year. B) a few (2-3 ) per year. C) ten per year. D) 20-30 per year. E) 100 per year.
Physics & Space Science