Question

The graph shows position as a function of time for two trains A and B running on parallel tracks. For times greater than t = 0, which of the following statement is true?

• A. At time t_B, both trains have the same velocity.
• B. Both trains speed up all the time.
• C. Both trains may have the same velocity at some time earlier than t_B.
• D. Graph indicates that both trains have the same acceleration at a given time.

Answer 1

The correct option is C

Both trains may have the same velocity at some time earlier than t_B.

As evident from the graph, slope of tangent PQ and slope of OA are equal. Hence B and A have same velocity at $t_1$ (which is less than $t_B$).