Sunspots occur in ______________ with the leading spot and the trailing spot having ________________ magnetic polarity
a. singles, same
b. pairs, opposite
c. singles, opposite
d. pairs, same
e. none of the others
b
You might also like to view...
Consider a small satellite moving in a circular orbit (radius r) about a spherical planet (mass M). The period does not depend upon
A) g at the satellite position. B) the planet mass. C) the satellite mass. D) the radius r. E) the universal gravitational constant.
A 30. N stone is dropped from a height of 10. m, and strikes the ground with a velocity of 13. m/s. What average force of air friction acts on it as it falls?
A) 7.2 N B) 2.9 N C) 1.2 N D) 4.1 N E) 0.13 KN
Which answer below is not a statement of the second law of thermodynamics?
a. Real processes proceed in a preferred direction. b. Energy does not flow spontaneously by heat from a cold to a hot reservoir. c. The entropy of the universe increases in all natural processes. d. In theory, heat engines working in a cycle employ reversible processes. e. You cannot construct a heat engine, operating in a cycle that does nothing but take heat from a reservoir and perform an equal amount of work.
Identical point charges Q are placed at each of the four corners of a 3.0-m × 4.0-m rectangle. If Q = 40 ?C, what is the magnitude of the electrostatic force on any one of the charges?
a. 3.0 N b. 2.4 N c. 1.8 N d. 3.7 N e. 2.0 N