please answer the question in pic related and explain how

Find the net force in the x direction, do the same for y, and then use the Pythagorean theorem to determine the net magnitude via arctan(y/x), but this is unnecessary given your answers.

For F1, remember the ratio for 30-60-90 triangles is {2x hypotenuse, 1x short side, sqrt(3) long side}. You could also use sin/cos on your calculator - just remember that the angle is -30, or sanity-check your answer to make sure the forces have the right sign.

>>352667
...I'm sorry but can you plase explain in simpler terms?

To find the horizontal force of F1 I used 80cos(30) and then for the vertical force of F1 is used 80sin(30), is what I'm doing right so far?

>>352698
That's fine, except the angle is -30. So you should flip that vertical force around, or just use sin(-30) instead of 30. I mentioned the ratio stuff because if I saw a problem like this, I wouldn't even bother with sin and cos because these angles have well known triangle ratios.

okay so I've found the Xres to be 31.28 and the Yres to be 23.68, and the hypotenuse ended up being 39.23N(which I think can be left as 40N which is answer no.5) but now how do I get the angle with respect to the X-axis?

I am doing a correspondence course assignment and my textbook hasn't come yet so everything I know is from the internet, therefore please assume I am not very knowledgeable about this subject

>>352743
Wrong answer. What forces are you adding together in the x and y directions? One of them should be 20, because F1 and F2 are -40 and 60 (F3 has no vertical force component).

>>352750
My calculations:

80cos(30)=71.28
80sin(-30)= -36.32(why does it have to be -30? Is it because downwards is positive?)

71.28- 40N=31.23
60-36.32=23.68

square root of (31.23)^2+(23.68)^2 = 39.19

This is my working

>>352768
*is it because downwards is negative

>>352768
>80cos(30)=71.28
>80sin(-30)= -36.32(why does it have to be -30? Is it because downwards is positive?)

These numbers are bogus, and I'm not sure how you're getting them. Even using a radian-only sin function, your numbers would be wrong but different to this. So how are you computing sin and cos?

Yes, it is -30 because your angle is going in the -y direction. If you imagine 0 degrees as positive X and go counterclockwise, then an angle of 330 is the same as -30. You should really be using -30 for the cosine function too, but in this case it doesn't affect your answer.

Go to Google, and search "sin 30 degree". Then do the same for cos. This will give you the correct answer. To solve this in the future, it's important to have a solid understanding of what sine,cosine and tangent actually are.

https://www.mathsisfun.com/sine-cosine-tangent.html

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>>352889
Oh, I figured it out. I forgot "grads" were a thing. Your calculator is set to use angular units that most of us don't care about and have never touched - press the "Deg" button wherever that is, and now when you run sin(30) you will get .5. When set to grads, you're essentially running sin(27) in degree units, which is what's throwing you off.

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>>352893
Oh my god you're right. I think I need to lie down for a second

>tfw you've been using the same calculator for 8 years and its been in the wrong setting which is why you failed high school and became a carpenter

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>>352647

Hope this helps.

>>352910
At some point you should've talked with a teacher/tutor/etc. and realized the mistake.