Question
Two trains of same length are running in parallel tracks
in the same direction with speed 85 km/hr and 105 km/hr respectively. The latter completely crosses the former in 36 seconds. Find the length of each train (in m).Solution
When two trains cross each other, they cover distance equal to the sum of their lengths with relative speed. Let's take length of each train = x So, total length of both trains = 2x Relative speed = (105 – 85) × (5/18) = 50/9 m/sec. ∴ Total length = Time × Relative speed ⇒ 2x = (36 × 50)/9 ⇒ x = 100 m
A liquid initially contracts when cooled down to 4°C but on further cooling down to 0°C, it expands. The liquid isÂ
Mendeleev's periodic table is based on ____?
Which of the following statements about permanent tissues is correct ?
Eclipses occur due to which optical phenomena?
Which part of the human brain controls involuntary actions like heartbeat and breathing?
Which vitamin is mainly obtained from sunlight and is important for healthy bones?
Which is not shown by vitamins?   Â
Which organ is often called the 'Powerhouse of the Cell'?
Which part of the plant is mainly responsible for the process of photosynthesis?
The speed of sound is maximum in which of the following ?