Net Force

[adrakdavra]

A 7N force and an 11N force act on an object at the same time. Which of the following CANNOT be the magnitude of the sum of these forces?
A) 2 N
B) 8 N
C) 12 N
D) 18 N
E) All of the values are possible

I know A is the answer, but why not B

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[Temperature101]

A 7N force and an 11N force act on an object at the same time. Which of the following CANNOT be the magnitude of the sum of these forces?
A) 2 N
B) 8 N
C) 12 N
D) 18 N
E) All of the values are possible

I know A is the answer, but why not B

Can not be higher than the sum or lower than difference of the two forces, but anything in between is good.

 

[Dipraman]

Can not be higher than the sum or lower than difference of the two forces, but anything in between is good.

This. You can have a partial force from each of the forces. Lets say you have 11 N acting on an object and some component of the 7 N force acting in another direction, which could make the net force 8 N
If all 7 N force is applied completely opposite to the 11 N force then your net force will be 11-7 thus 4 N. Thus lowest net force you can have is 4 N.