# vector problem 2

• Sep 2nd 2009, 04:22 PM
BiGpO6790
vector problem 2
You are to make four straight-line moves over a flat desert floor, starting at the origin of an xy coordinate system and ending at the xy coordinates (-149 m, 81 m). The x component and y component of your moves are the following, respectively, in meters: (20 and 60), then (bx and -70), then (-20 and cy), then (-60 and -70). What are (a) component bx and (b) component cy? What are (c) the magnitude and (d) the angle (relative to the positive direction of the x axis) of the overall displacement?
• Sep 4th 2009, 01:00 AM
aidan
Quote:

Originally Posted by BiGpO6790
You are to make four straight-line moves over a flat desert floor, starting at the origin of an xy coordinate system and ending at the xy coordinates (-149 m, 81 m). The x component and y component of your moves are the following, respectively, in meters: (20 and 60), then (bx and -70), then (-20 and cy), then (-60 and -70). What are (a) component bx and (b) component cy? What are (c) the magnitude and (d) the angle (relative to the positive direction of the x axis) of the overall displacement?

This is not really a calculus problem:
You are to make four straight-line moves

for the x vector sum
20 + bx - 20 - 60 = -149
(a) component: bx = 89

for the y vector sum
60 -70 + cy -70 = 81
(b) component: cy = 161

(c) magnitude = $\sqrt{ (-149)^2 + 81^2 }$

arctan (81/-149) = -0.4979radians ( = -28.5296 degrees )
& to make it positive (counterclockwise from zero, quadrant 1)
pi -0.4979radians = 2.6436radians ( = 151.4704 deg )

(d) the angle = 2.6436radians ( = 151.4704 deg )

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