Multiple choice

இரு ரயில்களின் நீளங்கள் முறையே 140 மீ மற்றும் 160 மீ ஆகும். அவை இணையான ரயில் பாதையில் மணிக்கு முறையே 60 கி.மீ மற்றும் 40 கி.மீ வேகத்தில் எதிரெதிர் திசையில் செல்கின்றன. அவை ஒன்றையொன்று கடக்க எத்தனை நொடிகள் ஆகும்? The lengths of the two trains are 140 m and 160 m respectively. They are traveling in the opposite direction at speeds of 60 km and 40 km, respectively, on parallel rail. How many seconds do they have to cross each other?

  1. 9 நொடிகள் / 9seconds

  2. 9.6 நொடிகள் / 9.6 seconds

  3. 10 நொடிகள்/10 seconds

  4. 10.8 நொடிகள்/10.8 seconds

  5. இவற்றில் ஏதுமில்லை/None of these

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Total distance = 140 + 160 = 300 m. Relative speed = 60 + 40 = 100 km/hr = 100 * (5/18) m/s = 500/18 m/s. Time = Distance / Speed = 300 / (500/18) = 300 * 18 / 500 = 3 * 18 / 5 = 54 / 5 = 10.8 seconds.

AI explanation

Using the formula for trains moving in opposite directions, the relative speed is the sum of their speeds: 60 kmph + 40 kmph = 100 kmph. Converting this to meters per second gives 100 multiplied by 5/18, which equals 250/9 m/s. The total distance to cross is the sum of their lengths, 140 m + 160 m = 300 m. The time is distance divided by speed, so 300 divided by 250/9 equals 10.8 seconds. The time taken is 10.8 seconds.