An equinox occurs when
a. neither end of earth’s axis is tilted toward or away from the sun.
b. the north end of earth’s axis is tilted away from the sun.
c. the north end of earth’s axis is tilted toward the sun.
d. earth’s axis is parallel to the sun’s rays.

A10nc charge sits at a point in space where the magnitude of the electric field is 1500 n/c. what will the magnitude of the field be if the 10 nc charge is replaced by a 20 nc charge? assume the system is big enough to consider the charges as small test charges.