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8 votes
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Mr. Mangan runs 50 m north in 5 seconds, 50 m east in 7 seconds, and50 m south in 3 seconds. What is his average speed? What is hisaverage velocity?

1 Answer

14 votes
14 votes

Mr. Mangan goes first in the north a distance


d_1=50\text{ m}

at time,


t_1=5\text{ s}

then towards east ,


d_2=50\text{ m}

in time,


t_2=7\text{ s}

after that he goes towards south a distance,


d_3=50\text{ m}

in time,


t_3=3\text{ s}

the average speed is,


\begin{gathered} s=\frac{total\text{ distance }}{\text{total time}} \\ =(50+50+50)/(5+7+3) \\ =10\text{ m/s} \end{gathered}

The average velocity is,


v=\frac{displacement}{\text{total time}}

Here the displacement is,


d^(\prime)=50\text{ m}

The average speed is,


\begin{gathered} v=(50)/(5+7+3) \\ =3.33\text{ m/s} \end{gathered}

The average velocity is,


v=3.33\text{ m/s along east}

User Rejeesh Rajan
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