Question

Shown in the figure are the velocity time graphs of the two particles $P_1$, and, $P_2$ Which of the following statements about their relative motion is true? Magnitude of their relative velocity :

• A. is zero
• B. is non zero constant
• C. continuously decreases
• D. continuously increases

Answer 1

Answer: (D)

continuously increases

Slope of a velocity time graph gives acceleration.
From the given graph we observe that acceleration of $P_1$ is greater than that of $P_2$. They both start off with the same velocity, because of the difference in their accelerations. $P_1$ keeps gaining higher velocities faster than $P_2$ and the difference of $V_1-V_2$ keeps increasing.
Hence, the relative velocity keeps increasing.