Finding Force Values Using Pythagorean Theorem

[slammer]

I have a question about those three forces. Let's say for example that f1x=0 and f1y=5 then f1=5 right? Or do I have to use the pathagorean therem to find f1 then it would be the square root of 5?

 

[hotcommodity]

The Pythagorean Theorem applies to right triangles. If one side is zero, you're no longer left with a triangle. The net force would be 5, since one component is zero. If both components were non-zero, you would use the Pythagorean Theorem.

 

[PhanthomJay]

In your example, since there is no x component, then fi = f1y =5. In general, however, use Pythagorus...f1 = sq rt of (f1x^2 + f1y^2) = sq. rt of (0^2 + 5^2) = sq rt of 25 = 5.