# 2 Vectors with Angles acting on an object

1. Oct 25, 2012

### JackandJones

Hey guys, I am having a little trouble determining the final answer to this question.

Basically an object is being pulled by two forces and I am suppose to find the Net Force

F1 = 12 N at an angle of 32 degrees (upwards)
F2 = 15 N at an angle of 24 degrees (downwards)

So what I did was split the two vectors and try to find Fnetx and Fnet y

For Fnetx = F1net + F2net

F1 = 12Cos(32)
F2 = 15 cos(24)

I added F1x and F2y and got
Fnetx = 23.87 N

For Fnety

F1y = 12sin32 = 6.36 N
F2y = 15sin24 = 6.10 N

I subtracted F1y-F2y because F2y is going in the negative direction so
Fnety = 0.26 N

I am not sure if I should add these together or use PT to get Fnet....then use Trig ratios to get the angle.... ?

Any ideas? I appreciate the help!

2. Oct 25, 2012

### AJ Bentley

You've now got the x and y components of a vector.
So how do you calculate the length and direction of the vector from them?

(You can't just add the lengths of the components - that would make no sense.)

3. Oct 25, 2012

### JackandJones

If I have Fnetx and Fnety

Would I use pythegorean theorem to find Fnet, and then Trig ratio to get the angle?

4. Oct 25, 2012

### Nytik

Exactly that.

5. Oct 25, 2012

### JackandJones

Okay perfect However could you please explain why I would not substract the F1y by the F2y?

Because F2y is a downward motion, it would not be negative?

6. Oct 25, 2012

### Nytik

You do subtract them; everything you have done up to this point is correct.

7. Oct 25, 2012

### JackandJones

Okay its just that the answer doesnt seem correct to me.

Fnetx = 23.87 N

Fnety = 0.26 N

Using PT:

Fnet = 23.87 N

Then then using Trig Ratios, the Angle = 0.62 degrees...... which doesnt seem correct..?

8. Oct 25, 2012

### Staff: Mentor

This thread has been moved to the "Introductory Physics" section of "Homework & Coursework Questions", where it should have been posted in the first place. Carry on, and try to remember to post similar questions here in the future.