No, I am not going to ask you what the difference between those two are. =P I know the differences, but at the beginning of this term, my class started to learn about electricity and magnets, and that stuff. Now, vector quantities are those that have direction and scalars are those without directions. But then my teacher says... to put a +/- in front of an answer if it is a scalar quantity and to not put anything in front of an answer if it is a vector quantity. What the heck? That really threw me off. Could someone clarify on why we need to do that please? @_@
I think your teacher means to leave the answer as is to indicate the direction of the field. Or to know what the direction is and to use the magnitude for the calculations.
your teacher put plus and minus sign to indicate directions.... if you going to put it in the cartesian plane it will have the positive and negative value of "x" or "y".
If a vector is defined by magnitude and direction, +ve is defined as in the same direction as the vector arrow points. What does putting a - in front do? Well, in what direction would do you say a car is moving if it is travelling at a velocity of -5 m/s to the right?