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

Your answer

The time of crossing is 4 s.

Explanation ,

Given ,

• Two trains travelling in the opposite direction having length ,

• Length of each train = 50 m

• Velocity of 1st train = 10 m /s

• Velocity of 2nd train = 15 m / s

So,

For Calculation ,

• The exact /total distance when they crossed each other ( D ) = 50 + 50 = 100 m.

• As the trains are travelling in opposite direction , So net relative velocity will be ( V ) = 15 - ( - 10 ) = 25 m/s

Now , we can calculate the time ( T ) easily by using the formula ,

• Velocity = Distance / Time

Time ( T ) will be ,

• Time ( T )= Distance ( D ) / Velocity ( V )

• T = 200 / 25 ( m x s / m )

• T = 4 s

Answer 2

Given:

• Length of two trains= 50m
• Velocity of one train = 10m/s
• Velocity of other train = 15m/ s
• In opposite direction

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

$\pink{\boxed{\boxed{d=\:100m}}}$

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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

$\pink{\boxed{\boxed{=25m/s}}}$

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

= distance ÷ velocity

= 100÷ 25 sec

$\huge{\red{\boxed{=4sec}}}$

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•°• Total time taken = 4seconds