the magnitude and direction of two vectors are shown in the diagram. what is the magnitude of their sum…

the magnitude and direction of two vectors are shown in the diagram. what is the magnitude of their sum? \noptions: 20, 6, $2\\sqrt{5}$, 8
Answer
Explanation:
Step1: Resolve vectors into x and y components
For the vector with magnitude 2 and angle (135^\circ) (from positive x - axis): The x - component (v_{1x}=2\cos135^\circ), and (\cos135^\circ =-\frac{\sqrt{2}}{2}), so (v_{1x}=2\times(-\frac{\sqrt{2}}{2})=-\sqrt{2}). The y - component (v_{1y}=2\sin135^\circ), and (\sin135^\circ=\frac{\sqrt{2}}{2}), so (v_{1y}=2\times\frac{\sqrt{2}}{2}=\sqrt{2}).
For the vector with magnitude 4 and angle (45^\circ) (from positive x - axis): The x - component (v_{2x}=4\cos45^\circ), and (\cos45^\circ=\frac{\sqrt{2}}{2}), so (v_{2x}=4\times\frac{\sqrt{2}}{2}=2\sqrt{2}). The y - component (v_{2y}=4\sin45^\circ), and (\sin45^\circ=\frac{\sqrt{2}}{2}), so (v_{2y}=4\times\frac{\sqrt{2}}{2}=2\sqrt{2}).
Step2: Find the resultant x and y components
The resultant x - component (V_x = v_{1x}+v_{2x}=-\sqrt{2}+2\sqrt{2}=\sqrt{2}). The resultant y - component (V_y = v_{1y}+v_{2y}=\sqrt{2}+2\sqrt{2}=3\sqrt{2}).
Step3: Calculate the magnitude of the resultant vector
The magnitude of a vector (\vec{V}) with components (V_x) and (V_y) is given by (|\vec{V}|=\sqrt{V_x^{2}+V_y^{2}}). Substitute (V_x = \sqrt{2}) and (V_y = 3\sqrt{2}) into the formula: [ \begin{align*} |\vec{V}|&=\sqrt{(\sqrt{2})^{2}+(3\sqrt{2})^{2}}\ &=\sqrt{2 + 18}\ &=\sqrt{20}\ &=2\sqrt{5} \end{align*} ]