Describe two situations in which opposite quantities combine to make zero

Question

I got this for math homework but I don't get it 

Answer 1

Hi Leonel

1. Two forces equal and acting in opposite direction result in zero force.

2.Sum of two moment of forces acting in opposite sense produce zero resultant.

 

Any two equal and opposite vectors produce zero net effect

Answer 2

Hi Leonel,

 

I think they are are talking about "additive inverses".  So a number like 3, when added to -3 would give you zero.

 

If you need situations, one I can think of is to dig a hole three feet deep.  The height of the hole is now -3 ft.   If you fill it with the 3 feet of dirt you took out of it, so you are adding 3 feet of dirt to the hole, now you are back at ground level which is a height of 0.

 

Could also use something like walking 10 yards to the north (+10)  then pivoting and walking 10 feet south (-10) and you end up right where you started, having traveled 0 yards.

 

Is that the kind of thing your teacher is asking?