Question

The speed of train is 72 km per hour find its speed in metre per second

Answer 1

speed in m/s=72×5/18
=20m/s

Answer 2

$\huge\sf\pink{Answer}$

☞ Speed in m/s = 20m/s

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$\huge\sf\blue{Given}$

✭Speed of train in km/h = 72 km/h

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$\huge\sf\gray{To \:Find}$

❍ Speed in m/s?

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$\huge\sf\purple{Steps}$

To change it into metre/seconds, there is method used is,

Simply multiply it with \sf \dfrac{5}{18}

➝ $\sf 72 ×\dfrac{5}{18}$

➝ 4 × 5

➝ $\sf\green{20\: m/s}$

☆ To find why we ae multiplying with $\sf\dfrac{5}{8}$

We know that,

◕ 1 km = 1000 m

◕ 1 hr = 3600 secs

So,

$\leadsto \sf72 \times \frac{1000}{3600} \\ \\ \leadsto\sf72 \times \frac{5}{18} \\ \\ \leadsto \sf\green{20 \: ms {}^{ - 1}}$

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