Question

In above shown graph of position versus time, two trains, X and Y are moving on parallel track from the same starting position from the rest. Which of the following statements is true?

• A. Train Y moves faster than train X at all points on the graph
• B. Train X moves faster than train Y at all points on the graph
• C. Train X will reach the distance $d_2$ before train Y
• D. Train Y will reach the distance $d_2$ before train X
• E. The trains will reach the distance $d_2$ at the same time.

Answer 1

The correct option is C Train X will reach the distance $d_2$ before train Y

According to the graph, both trains are at same position at time $T$.

The slope of the curve under position-time graph gives the instantaneous velocity of the object.

At the instant $T$, the slope of curve X is greater than that of Y.

Hence at time $T$, train X has greater velocity than train Y and is increasing with time whereas train Y has constant velocity.

Thus train X will reach the distance $d_2$ before train Y.