anonymous 4 years ago The displacement vectors A and B, when added together, give the resultant vector R, so that R = A + B. Use the data in the drawing and the fact that phi = 34° to find the magnitude R of the resultant vector and the angle θ that it makes with the +x axis. R = m θ = °

1. anonymous

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2. anonymous

would 4 cos 34 be R? from using law of cosines ?

3. asnaseer

|dw:1327258762765:dw| \begin{align} h&=8\sin(34)\tag{1}\\ x&=8\cos(34)\tag{2}\\ R^2&=x^2+(6-h)^2\tag{3}\\ \theta&=\arctan(\frac{6-h}{x}\tag{4}) \end{align}Use (1) and (2) to calculate h and x. Then use these to work out the magnitude or R in (3). Finally use (4) to find $$\theta$$. BTW: $$\arctan$$ is just the inverse tangent function. Sometimes also written as $$\tan^{-1}$$