posted by physics .
Two point charges, initially 1 cm apart, are moved to a distance of 3 cm apart. By what factor do the resulting electric and gravitational forces between them change?
Two positive charges, each of magnitude q, are on the y-axis at points y = +a and y = -a. Where would a third positive charge of the same magnitude be located for the net force on the third charge to be zero?
a. at the origin
b. at y = 2a
c. at y = -2a
d. at y = -a
Which is the MOST correct statement regarding the drawing of electric field lines?
a. electric field lines always connect from one charge to another
b. electric field lines always form closed loops
c. electric field lines can start on a charge of either polarity
d. electric field lines can never cross each other