Question

The displacement-time graphs of two particles A and B are straight lines making angles of respectively ${30}^0$ and ${60}^0$ with the time axis. If the velocity of A is $v_A$ and that of B is $v_B$, then value of $\frac{v_A}{v_B}$ is:

• A. $1/2$
• B. $1/\sqrt{3}$
• C. $\sqrt{3}$
• D. $1/3$

Answer 1

Answer: (D)

$1/3$

Slope of displacement - time graph gives the velocity of particle.

So, velocity of particle A: $v_A=\tan {30}^0$ and velocity of particle B: $v_B=\tan {60}^0$
$\therefore \frac{v_A}{v_B}=\frac{\tan {30}^0}{\tan {60}^0}=\frac{1/\sqrt{3}}{\sqrt{3}}=\frac{1}{3}$