On a position vs. time graph for an object, a horizontal line segment indicates that the object is(1 point) moving at a constant rate.
moving at a constant rate.

at its starting location.
at its starting location.

not moving and is at rest.
not moving and is at rest.

located at ground level.

moving at a constant rate. (could be zero m/s)

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.

what type of charge does it have? negative