A boy runs first 100m with a unifrom speed of 8m/s and the next 200m with a uniform speed of 5m/s. cal culate the avarge speed of the boy?

Dear Student,

Kindly find the answer to your asked query.

$$\begin{gathered} Average speed=\frac{total dis\tan ce travelled}{total time taken} \\ {s}_1=100 m \\ {v}_1=8 m/s \\ {t}_1=\frac{s_1}{v_1}=100/8=12.5 s \\ {s}_2=200 m \\ {v}_2=5m/s \\ {t}_2=\frac{s_2}{v_2}=\frac{200}{5}=40s \\ average speed = \frac{s_1+s_2}{t_1+t_2}=\frac{100+200}{12.5+40}=\frac{300}{52.5}=5.71 m/s \end{gathered}$$

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