A man walks $20 k m$ in $4 h$ . Find his speed in $k m h^{- 1}$ . Convert it to $m s^{- 1}$

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Solution

Speed

$v = \frac{s}{t}$

$v = \frac{20}{4} k m / h$

$v = 5 k m / h$

The speed in $m / s$ is given by

$v = 5 \times \frac{5}{18}$

$v = \frac{25}{18}$

$v = 1.4 m / s$

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