Occasionally Parts of the Lunar Surface Develop an Electric Field

Multiple Choice

Occasionally parts of the lunar surface develop an electric field 20 kN/C,allowing dust particles that have been charged by cosmic rays to become levitated.How many electrons must be placed on a 1.0-g dust particle if it is to be levitated in this field? The acceleration due to gravity on the surface of the moon is 1.62 m/s².

A) 3.2 * 10⁷
B) 5.1 * 10¹¹
C) 3.2 * 10¹⁴
D) 8.9 * 10²²
E) 2.0 * 10³⁸