Can you please explain how to find the direction for 9 a) it should be arctan(-1
ID: 1573566 • Letter: C
Question
Can you please explain how to find the direction for 9 a) it should be arctan(-1/-2) which equals 26.56 degrees however that isn't the answer leaving me really stumped.
9. 2/8 points | Previous Answers SerPSE9 3.P.031 FB.WI Consider the three displacement vectors A = -3 B- 31-3) and C : ( 9 +5) m Use the component method to determine the following. Take the +r direction to be to the right.) 4 (a) the magnitude and direction of the vector D-A-B-C magnitude2.24 direction The angle you give does not put the sum into the correct quadrant.° counterclockwise from the +x axis (b) the magnitude and direction of E-A B C magnitude direction o counterclockwise from the +x axisExplanation / Answer
a) D = A + B + C
= (4i - 3j) + (3i - 3j) + (-9i + 5j)
= -2i - j
magnitude of D, |D| = sqrt(2^2 + 1^2)
= 2.24 m
direction : theta = 180 + tan^-1(((-1)/(-2))
= 26.6 degrees from -x axis in counter clockwise direction.
= 180 + 26.6 degrees from +x axis in counter clockwise direction.
= 206.6 degrees from +x axis in counter clockwise direction.
b) E = -A - B + C
= -(4i - 3j) - (3i - 3j) + (-9i + 5j)
= -16i + 11 j
magnitude of E, |D| = sqrt(16^2 + 11^2)
= 19.4 m
direction : theta = tan^-1(11/(-16))
= -34.5 degrees
= 34.5 degrees from -x axis in clockwise direction
= 180 - 34.5 degrees from +x axis in counter clockwise direction.
= 145.5 degrees counter clockwise from +x axis.
Hope you got it now. :)