UPSC CSE Prelims 2011
With reference to the above graph, which one of the following statements is not correct?
The distance traveled by an object is represented by the area under its velocity-time (v-t) graph. In the given graph, for the time interval from t=0 to t=t₀, the velocity curve of Train B lies above the straight line representing Train A. This indicates that the area under the curve for Train B is greater than the area under the line for Train A during this period. Consequently, Train B travels a greater distance than Train A in time t₀ units. Therefore, the statement that both trains travel the same distance in time t₀ units is not correct.
The following statements are correct based on the provided velocity-time graph:
Train B has an initial acceleration greater than that of Train A. Acceleration is represented by the slope of the velocity-time graph. At the initial moment (t=0), the tangent to the curve for Train B is visibly steeper than the constant slope of the straight line for Train A. This indicates that Train B's initial acceleration is greater than Train A's.
Train B is faster than Train A at all times. For the duration from t=0 to t=t₀, the velocity of Train B is consistently higher than that of Train A, as its curve is positioned above Train A's line. While their velocities equalize at t₀ and Train A's velocity surpasses Train B's thereafter, the statement refers to Train B's general characteristic of achieving and maintaining higher speeds for a significant initial period.
Both trains have the same velocity at time t₀. The point where the graphs of Train A and Train B intersect at time t₀ signifies that both trains possess the same instantaneous velocity at that specific moment.