Wine made from fossil fuels is not radioactive because
A. the radioactivity has decayed away
B. there is no carbon in such wine
C. ancient plants never were radioactive
D. the half-life of the key elements is too long
Answer: A. the radioactivity has decayed away
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When an electron is in a magnetic field, different spin states associated with the electron's magnetic moment will occur. What are these states called?
a. up, down c. clockwise, counterclockwise b. plus, minus d. north, south
If the back of a person's eye is too close to the lens, this person is suffering from
A) nearsightedness. B) spherical aberration. C) astigmatism. D) chromatic aberration. E) farsightedness.
The diameter of the sun is 1.39*109 m. Estimate the percentage of the total radiation emitted by the sun, which approximates a blackbody at 5760 K, that is actually intercepted by the Earth. Of the total radiation falling on the Earth, about 70% falls on the ocean. Estimate the amount of radiation from the sun that falls on land, and then estimate the ratio of energy currently used worldwide and the amount of terrestrial solar energy that is available. Discuss why all of the energy cannot be harnessed.
GIVEN • Diameter of sun (Ds)= 1.39*109 m • Sun is approximate black body at temperature (Ts) =5760 K • 70% of radiation falls on the ocean. • Diameter of the earth (De)= 1.27*107 m • Distance between sun and earth (Rse )=1.53*1011 m FIND • Amount of radiation from sun that falls on land • Ratio of energy currently used worldwide and the amount of terrestrial solar energy that is available. • Discuss why all energy cannot be harnessed. ASSUMPTIONS • The sun’s radiation is assumed as ideal black body radiation.
What is the solar thermostat?
What will be an ideal response?