# Static Equilibrium [closed]

A 3 Newton force and a 4 Newton force are acting concurrently on a point. Which force could not produce equilibrium with these two forces?

1. 1N
2. 7N
3. 9N
4. 4N

I'm confused. The book I'm looking at says that a 9 Newton force could not produce equilibrium with a 3 Newton and a 4 Newton force, but gives no clear explanation of why that is, could someone please explain? Thanks.

• Research the triangle inequality. Jan 31, 2016 at 0:20
• In addition to Bill's correct comment (which relies on the notion that vectors are forces) it might be worth explicitly constructing the cases cor the 1 and 7 Newton forces. The think about why neither 9 not 0.5 Newtons can do the trick. Jan 31, 2016 at 0:40

## 1 Answer

The max resultant force for these two forces would occur if they were both acting along the same line in the same direction. In that case they add algebraically. 3+4 = 7. Any other configuration of the forces gives an answer less than that.