whats R? A 3m south of east B 3m north C 3m 30 degrees north east D 3m 50 degrees south west
what's the general question ? ^_^
whats R? Magnitude of R and direction of R.
how can we determine the magnitude of R and direction of R if there's no problem lol?
i can show you a sample of a previous problem and how it's done.
Nikolas Oman April 17 at 6:46pm best way to resolve each vector into perpendicular components. i = positive horizontal direction (to the right) j = positive vertical direction (up) A = -5 cos 65 i + 5 sin 65 j B = 5 cos 50 i - 5 sin 50 j C = -5 cos 45 i - 5 sin 45 j R = A + B + C = (-5 cos 65 + 5 cos 50 - 5 cos 45) i + (5 sin 65 - 5 sin 50 - 5 sin 45) j R = -2.435 i - 2.834 j Now use the Pythagorean Theorem to get the magnitude: Magnitude of R = √(2.435² + 2.834²) = 3.7 m Direction of R = arctan(-2.834/-2.435) = 229.3° ... so that's 49.3° south of west
that's the question? :)
no thats another problem. question is whats the magnitude and direction of R if vectors are: A 3m south of east B 3m north C 3m 30 degrees north east D 3m 50 degrees south west
LOL >_< my bad, I thought those were the choices ^^"
lol no do you know how to do it?
I'll give it a try? :)
tnx :)
np ^_^
remind me, In the previous problem, A = -5 cos 65 i + 5 cos65 j < -- angles were given? or is that the general form
angles were given
how about for this problem?
A 3m south of east B 3m north C 3m 30 degrees north east D 3m 50 degrees south west
this is all that's given
hmm, that means that you have to figure out the angles from the given
B is easy, 3 m north , angle = 90 degrees
hmm yea and A? 45 degrees?
since they haven't given you the angles, yes you can assume that A = 45 degrees
and now? how much is R?
all you've got to do is use the same way you've used in the previous question :) I think your prob was trying to figure out the angles? right?
well it's not my homework :) it's my friends homework and I have no idea how to do it :)
lol >_<
Alright, let's try to solve it together ^_^
she solved it and got 2.79m 1.65 degrees north of east and she just wants to check if it's ok
so: i = positive horizontal direction (to the right) j = positive vertical direction (up) then we can say the following : A = 3 cos 45 - 3 sin 45 B = 3 sin 90 C = 3 cos 30 + 3 sin 30 D = - 3 cos 50 - 3 sin 50
yep i agree so far
now: R = A + B + C = (3 cos 45 - 3 sin 45 ) + (3 sin 90 ) + (3 cos 30 + 3 sin 30) + (-3 cos 50 - 3 sin 50) = 0 + 3 + pi - 4.23 = 1.912
R= 3 cos 45 + 3 cos 30 - 3 cos 50)i + (3 sin 45 + 3 sin 90 + 3 sin 30 - 3 sin 50)j
lol, wait, I've messed it up
yeah, hold on :)
ok
R = 1.76 i - 3.32 j I might have some calculation mistakes, it happens ^_^
so this is it?
\[R = \sqrt((1.76)^2 + (3.32)^2)\] = 3.74 m
alright thank you so very much!
arctan = -62.07
np :)
thank you thank you so her answer was wrong?
I'm not sure what was her answer lol , I just followed the steps and given :)
ok thank you!
np ^_^, but I'm not sure though ^^"
is there an online calculator where i could check this?
there's your hand-calculator? :)
i dont have it :/
can you calculate this for me please? R = (3 cos 45 + 3 cos 30 - 3 cos 50)i + (-3 sin 45 + 3 sin 90 + 3 sin 30 - 3 sin 50)
I did lol, that's what I got, answer above
you can check with your calculator if you want :)
oh ok thank you again :)
lol, np ^_^
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