2006-07-27 15:58:17 · 3 answers · asked by Z R 1 in Science & Mathematics ➔ Mathematics
Considering a is down the x axis then a= 14* cos(120)
a= -14 * cos 60 a= -7
b= 14 sin(120) = 7 sqrt(3)
Verify: sqrt(7^2+3*7^2) =14
So u = -7i + 7sqrt(3) j
2006-07-27 19:43:28 · answer #1 · answered by Roxi 4 · 0⤊ 0⤋
(sqrt(3)/2)*14i - (1/2)14. it's a 60 degree angle from the negative x axis, so it's a 30/60/90 triangle. the ratios for these triangles are sqrt(3)/2:1/2: 1. multiply by 14 (magnitude of vector) and there's your answer.
2006-07-27 16:06:37 · answer #2 · answered by turducken 2 · 0⤊ 0⤋
Opp. = Hy. SinΘ
= 14 Sin 120º
= 14 ( 0.8660...)
= 12.1243..
Ady. = Hy. CosΘ
= 14 Cos120º
= 14 (-0∙5)
= -7
ai + bj = -7i + 12.1243..j
2006-07-27 21:37:43 · answer #3 · answered by Brenmore 5 · 0⤊ 0⤋