Question

A point object is moving with velocity $v_0=10\hat{i}\text{m}/\text{s}$ along x-axis as shown in figure. Relative velocity of its image in mirror $M_1$ with respect to mirror image velocity in $M_2$ is :

(Take $\text{sin}{37}^{\circ }=0.6$)

• A. 9 m/s
• B. 10 m/s
• C. 12 m/s
• D. 15 m/s

Answer 1

The correct option is C

12 m/s

$\overrightarrow{v_{1i}=-10\hat{i}}$

$\overrightarrow{v_{2i}}=(6\text{cos}{53}^{\circ }-8\text{cos}{37}^{\circ })\hat{i}+(6\text{sin}{53}^{\circ }+8\text{sin}{37}^{\circ })\hat{j}$

$=(3.6-6.4)\hat{i}+(4.8+4.8)\hat{j}$

$=-2.8\hat{i}+9.6\hat{j}$

${\overrightarrow{v}}_{12}=-7.2\hat{i}-9.6\hat{j}$

$v_{12}=\sqrt{{7.2}^2+{9.6}^2}$

$=2.4\sqrt{3^2+4^2}$

$=12\text{m/s}$