Help with vectors question
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5. question is : Determine - by calculation - the magnitude and direction of the resultant forces.
F1 = 25 < 102 degrees
F2 = 30 < 40 degrees
F3 = 20 < 133 degrees
And is question four correct if i add the arrows going from F1 to F2 and F2 to (0,0) ?
Hi John:
How do you interpret the phrase "resultant forces"? If the phrase was "resultant force" (singular), then I would read the question as asking for the net force resulting from F1, F2, and F3. (Typo, maybe?)
I don't think so. It looks to me like your F2 is not correctly positioned (or, you're adding instead of subtracting).
F1 - F2 is the same as F1 + -F2
Here's an image of A - B. Note how the direction of -B is opposite the direction of B.
Cheers :cool:
Hi Quaid
On question 4 i was adding instead of taking away my mistake. i have had another go what do you think?
and on question 5 it does say forces here is my working of how i think you do it
Hi John:
Yes, I agree with your interpretation; they want the force which results from the combination of F1, F2, and F3.
However, the given diagram looks as though F1's head is at the origin, yes? I'm not seeing a negative sign in front of F1's magnitude (it's hard to decipher the image). What do you think?
(John, consider using a higher-resolution scanner-setting, if available. Or, take individual pics. Or, take screen shots (of various sections) of what you see clearly on your screen, and attach those images individually. In the forum guidelines, they request that multiple exercises be posted in separate threads, anyway, so the individual uploads would help with the blurry-image issue.)
Cheers :cool:
EDIT: My answer agrees with your latest work on exercise 4.
Yes, I agree with your interpretation; they want the force which results from the combination of F1, F2, and F3.
However, the given diagram looks as though F1's head is at the origin, yes? I'm not seeing a negative sign in front of F1's magnitude (it's hard to decipher the image). What do you think?
(John, consider using a higher-resolution scanner-setting, if available. Or, take individual pics. Or, take screen shots (of various sections) of what you see clearly on your screen, and attach those images individually. In the forum guidelines, they request that multiple exercises be posted in separate threads, anyway, so the individual uploads would help with the blurry-image issue.)
Cheers :cool:
EDIT: My answer agrees with your latest work on exercise 4.
Last edited:
Hi John:
Yes, I agree with your interpretation; they want the force which results from the combination of F1, F2, and F3.
However, the given diagram looks as though F2's head is at the origin, yes? I'm not seeing a negative sign in front of F2's magnitude (it's hard to decipher the image). What do you think?
(John, consider using a higher-resolution scanner-setting, if available. Or, take individual pics. Or, take screen shots (of various sections) of what you see clearly on your screen, and attach those images individually. In the forum guidelines, they request that multiple exercises be posted in separate threads, anyway, so the individual uploads would help with the blurry-image issue.)
Cheers :cool:
EDIT: My answer agrees with your latest work on exercise 4.
head is at the origin but that is F1 in the middle. F2 is on the right hand side and F3 on the left hand side. The are however no negative signs in front of the magnitude of any so i just completed the question without negatives? what answers did you get without negatives?
Yes, of course. (My typo.)
If I were a student again, I would provide each version to the instructor (along with an explanation).
I haven't done that, yet.
Your arithmetic looks okay.
-5.19 should be rounded as -5.20
14.62 should be rounded as 14.63
If you desire to report the final answer using approximations to 2 decimal places, I recommend rounding to 4 places, during intermediate steps.
Thanks for your help quaid