Question

Two trains each 50 m long are traveling in opposite direction with velocity 10 mps and 15 mps.the time of crossing is=???

Answer 1

Given:

• Length of two trains= 50m

• Velocity of one train = 10m/s

• Velocity of other train = 15m/ s

• In opposite direction

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Find:

• The time of crossing

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Solution:

Let the effective distance which need to be covered to be crossed over = d

d= total length of two trains

d= 50m+ 50m

$\purple{\boxed{\bold{d=\:100m}}}$

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• Velocity of one train = 10m/s

As the trains are travelling in opposite direction

• then, let the velocity of other train be = (-15)m/s

Thus total effective velocity

=10-(-15)m/s

=10+15m/s

$\purple{\boxed{\bold{=25m/s}}}$

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Time taken to travel 100m with velocity of 25m/s

= distance ÷ velocity

= 100÷ 25 sec

$\large{\red{\boxed{\bold{=4sec}}}}$

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•°• Total time taken = 4seconds