Question

The maximum and the minimum magnitudes of the resultant of two given vectors are 17 unit and 7 unit respectively. If these two vectors are at right angles to each other, the magnitude of their resultant is -

• A. 14
• B. 16
• C. 18
• D. 13

Answer 1

Answer: (D)

13

Answer 2

Q A + B = 17

& A – B = 7 Ž $\begin{matrix} \begin{aligned} & A = 12 \\ & B = 5 \end{aligned} \end{matrix}$

Q $\theta = 90^{0}$

\ $R = \sqrt{A^{2} + B^{2}} = \sqrt{12^{2} + 5^{2}}$ = 13 unit