Question

 A 150 m long train moves towards south at a speed of 10 m/s. A sparrow flying at a speed of 5 m/s towards north crosses the train. What is the time taken by the sparrow to cross the train ?​

Answer 1

Diagram :-

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Solution :-

The sparrow is going towards north direction & the train is going towards south direction .

So ,the total speed of train & sparrow is

10 m/s + 5m/s = 15m/s

So , now finding time taken

Speed = $\sf\dfrac{Distance}{Time}$

Simplifying ,

Time = $\sf\dfrac{Distance}{speed}$

Substituting ,

• Distance = 150m
• Speed = 15m/s

$\sf\leadsto Time = \dfrac{150}{15}$

$\sf\leadsto Time = \underline{\boxed{\textbf{\textsf{10s}}}}$

Hence , time taken by the sparrow cross the train = 10s

Answer 2

Diagram :

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Answer:

• Distance to be covered by the sparrow = 150 m

• Speed of train = 10 m/s

• Speed of Sparrow = 5 m/s

Therefore, Total Distance = 10 + 5 = 15 m/s

Now, use the given below formula to Calculate Time taken (t) by the Sparrow to cross the train.

$:\implies \sf Time = \dfrac{Distance}{Total \: Time \: taken}$

Now,Plug in the given values in above given formula :

$:\implies \sf Time = \dfrac{150}{15}$

$:\implies \underline{ \boxed{\textsf{ \textbf{ Time = 10 seconds}}}}$

$\therefore\underline{\textsf{The time taken by the sparrow to cross the train is \textbf{10 seconds}}}.$