Question

Shown in the figure are the position time graph for two children going home from the school. Which of the following statements about the relative motion is true after both of them started moving? Considering 1-Dimensional motion, their relative velocity

• A. first increases and then decreases
• B. first decreases and then increases
• C. is zero
• D. is non zero constant

Answer 1

The correct option is D is non zero constant

Slope of a displacement time graph gives us velocity.
Here for both the children the graphs are straight lines (constant slope)
Hence both the children have constant velocities. But they are not equal (different slopes).
Hence relative velocity $v_2-v_1=constant\left(nonzero\right)$
Hence option D is correct.