Question

A train 100m long is movingwith velocity of 72km/hr How much time it take to cross 1km bridge​

Answer 1

Given:-

• Length of train = 100m
• Speed/velocity of train = 72km/hr
• Length of bridge = 1km.

To Find:-

• Time taken by train to cross the bridge.

Solution :-

Total distance to cross the bridge will be,

⇒ Total distance = 1km + 100m

⇒ Total distance = 1000m + 100m

⇒ Total distance = 1100m

Speed of train,

= 72km/h

= 72×1000/60×60 m/s

= 72000/3600 m/s

= 20m/s

Time = Distance/Speed

⇒Time = 1100m /20m/s

⇒Time = 55 s

Therefore, time taken by the train to cross the bridge is 55 seconds.

Answer 2

$\huge\sf ➲{\underline{ \underline \color{darkgreen}{Given}}} \\ \\ \ast \: \: \bf Length \: of \: the \: train \: \longrightarrow \:\red{ 100 \: m}$

$\ast \: \: \bf Velocity \:or \: speed \: of \: the \: train \: \longrightarrow \:\red{ 72 \: km/ \: h}$

$\: \ast \: \: \bf Length \: of \: the \: bridge \: \longrightarrow \:\red{ 1 \: km}$

$\huge\sf ➲{\underline{ \underline \color{darkgreen}{To \: find \: }}} \\ \\ \\ \ast \: \: \bf Time \: taken \: by \: the \: train \: to \: cross \: the \: bridge \longrightarrow \: \large\red{ ?}$

$\: \huge\sf ➲{\underline{ \underline \color{darkgreen}{Solution}}} \\ \\ \\ \tt Total \: distance \: to \: cross \: the \: bridge- \\ \\ {\boxed{ \bf NOTE:-}} \\ \\ \large\bigstar {\underline{ \overline{ \bf 1 \: km \: = \: 1000 \: m}}} \bigstar$

$\large \bf{➯Total \: distance \:= \: Length \: of \: the \: train + \: Length \: of \: the \: bridge}$

$\large \bf{➯Total \: distance \:= \: (100 + \: 1000) m}$

$\large \bf{➯Total \: distance \:= \:1100 \: m}$

$\\ \tt \: \: Now, \: we \: \: will \: \: find \: the \: \: speed \: \: of \: the \: train \:$

$\large \bf{➯Speed \:= \: 72 \: km/h}$

$\large \bf{➯Speed \:= \frac{72 \times 1000 \: m}{60 \times 60 \: \: \: \: \: s} }$

$\large \bf{➯Speed \:= \: \frac{720 \cancel{0} \cancel{0} \: m}{36 \cancel0 \cancel0 \: \: \: \: s} }$

$\large \bf{➯Speed \:= \: 20 \: m/s }$

$\\ \tt \: Now, \: we \: \: will \: \: find \: \: the \: \: time \: \: taken \: by \: applying \: the \: formula -$

$\bigstar {\underline {\boxed { \bf {\green\:{ \red{ Time}= \frac{ \purple{Distance}}{ \green{Speed}} }}}}} \bigstar$

$\longrightarrow{ \bf {\green\:{ \red{ \large \: Time}= \large\frac{ \purple{ \large110 \cancel0 \: \cancel{m}}}{ \large\green{2 \cancel0 \: \cancel{m}/s}} }}}$

$\longrightarrow {\underline {\boxed { \bf {\green\:{ \red{ Time}{ = 55 s } }}}}}$

$\large \bf \therefore \: it \: will \: take \: 55 \: seconds \: to \: cross \: the \: bridge$

$\\ \bigstar{ \underline{ \underline \pink{ \sf★@iTzShInNy☆}}} \bigstar$