Plus and minus signs are used in one-dimensional motion to indicate direction. what is the sign of an acceleration that reduces the magnitude of a negative velocity? of a positive velocity?

Positive sign for negative velocity and minus sing for positive velocity

Explanation:

In the case of the negative velocity, the sign of the acceleration that reduces its magnitude is the positive sign, since being in the opposite direction  to the movement indicates a deceleration or braking. In the case of the positive velocity, the sign of the acceleration that reduces its magnitude is the negative sign, since being in the  opposite direction to the movement indicates a deceleration or braking. We observe that there will always be a reduction in the magnitude of the velocity if the acceleration goes in the opposite direction.

15.3 cos 65 degrees trig

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it