Question

Two cars A and B are moving with same constant
speed 5 m/s in opposite direction. The relative velocity
of car A w. r. t car B is
O Zero
10 m/s
O 12 m/s
5 m/s​

Answer 1

Answer

10m/s

The relative velocity between the cars A and B is 10m/s

$\bf\large\underline{Solution}$

Given, the magnitude of the velocities of A and B

$\sf |\overrightarrow{A} | =A = 5m {s}^{ - 1}$

$\sf |\overrightarrow{B} | =B = 5m {s}^{ - 1}$

Since, the cars A and B are in opposite directions so , the angle between them is

θ = 180°

Therefore , relative velocity between A and B is :

$\sf\implies R = \sqrt{A^{2} + B^{2} + 2AB\cos\theta} \\\\ \sf\implies R = \sqrt{ 5^{2} + 5^{2} - 2\times 5 \times 5 (\cos180\degree)} \\\\ \sf\implies R = \sqrt{25 + 25 - 2 \times 25 (-1) } \\\\ \sf\implies R = \sqrt{25(1+1+2)} \\\\ \sf\implies R = \sqrt{5^{2} \times 2^{2}} \\\\ \sf\implies R = 5\times 2 \\\\ \sf\implies R = 10$

Therefore , the relative velocity between the cars A and B is 10m/s.

Answer 2

Answer:

10m/s

pls mark as brain