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Texas Instruments technical mcq question, verified with a worked answer. Free to practise - no sign-up.
Trains A and B** Two trains A and B are running on parallel tracks in the same direction. The length of A is 65 m and it is running at a speed of 34 km/hr. The length of B is 70 m and it is running at a speed of 25 km/hr. How long will it take for both the trains to pass each other completely from the moment they meet?
Show answer & explanation
Relative speed is 34 - 25 = 9 km/h = 2.5 m/s. Total distance to pass completely is 65 + 70 = 135 m. Time = 135 / 2.5 = 54 seconds.
Step-by-step Derivation:
Step 1: Relative speed in same direction = 34 km/h - 25 km/h = 9 km/h.
Step 2: Convert to m/s: 9 * (5/18) = 2.5 m/s.
Step 3: Total distance to clear each other = L_A + L_B = 65 m + 70 m = 135 m.
Step 4: Time taken = Distance / Relative Speed = 135 / 2.5 = 54 seconds.