In the pie chart below, which of the following represents the amount of Earth's surface covered by water? A only
B only
B and C
D only

A

Explanation:

two charges are fixed in place on the x-axis as shown. the charge at x = 0 is negative and has magnitude q = 2 μcoulombs (1 μcoulomb = 10-6 coulombs). the charge at x = d, (d = +12 cm), is positive and has magnitude q = 4 μcoulombs. find a point x = xo along the x-axis at which the electric field is zero.

found in the nucleus

has mass of one amu