Question

A train of length 50m is moving with a constant speed of 10m/s Calculate the time taken by the train to cross an electric pole and bridge of length 250 m. (5s , 30s)​

Answer 1

Given

• Length of the train = 50 m
• Speed= 10 m/s
• Length of electric pole = 250 m

To Find

• Time taken to cross the pole and bridge

Solution

☯ Speed = Distance/Time

• We shall first find the total distance and then the time taken to cross the bridge

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✭ According to the Question :

➞ Speed = Distance/Time

➞ 10 = 50/Time

➞ Time = 50/10

➞ Time (Crossing Pole) = 5 sec

• Also to find the time taken to cover the bridge we shall we the length of the train and the length of the bright, then use the formula and find the time taken.

➞ Total Distance = Length of the train + Length of the bridge

➞ Total Distance = 50 + 250

➞ Total Distance = 300 m

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Therefore the Time taken to cross the bridge would be,

➞ Speed = Distance/Time

➞ 10 = 300/Time

➞ Time = 300/10

➞ Time = 30 sec

Answer 2

Explanation:

$\frak Given = \begin{cases} &\sf{Length\ of\ the\ train\ =\ 50m.} \\ &\sf{Speed\ =\ 10m/s.} \\ &\sf{length\ of\ the\ electric\ pole\ =\ 250m.} \end{cases}$

To find:- We have to find the time taken to cross electric pole and bridge ?

__________________

$\frak{\underline{\underline{\dag As\ we\ know\ that:-}}}$

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

__________________

$\frak{\underline{\underline{\dag By\ substituting\ the\ values,\ we\ get:-}}}$

$\sf : \implies {10\ =\ \dfrac{50}{Time}} \\ \\ \sf : \implies {Time\ =\ \cancel \dfrac{50}{10}} \\ \\ \sf : \implies {\purple{\underline{\boxed{\bf Time\ (Crossing\ pole)\ =\ 5sec.}}}}\bigstar$

☯️ So, now we will calculate the total distance to find the total time taken.

$\sf : \implies {Total\ distance\ =\ length\ of\ the\ train\ +\ length\ of\ the\ bridge} \\ \\ \sf : \implies {Total\ distance\ =\ 50\ +\ 250} \\ \\ \sf : \implies {\purple{\underline{\boxed{\bf Total\ distance\ =\ 300m.}}}}\bigstar$

$\frak{\underline{\underline{\dag Finding\ time\ taken\ to\ cross\ the\ bridge:-}}}$

$\sf : \implies {Speed\ =\ \dfrac{Distance}{Time}} \\ \\ \sf : \implies {10\ =\ \dfrac{300}{Time}} \\ \\ \sf : \implies {Time\ =\ \cancel \dfrac{300}{10}} \\ \\ \sf : \implies {\purple{\underline{\boxed{\bf Time\ =\ 30sec.}}}}\bigstar$

Hence:-

$\sf \therefore {\underline{The\ required\ time\ is\ 30sec.}}$