Question

a person travel along a straight road for the first half length with velocity v1 and the second half length with a velocity v2 .find the mean velocity.

Answer 1

Hi there,

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Average velocity < v_{avg} > = total displacement ÷ total time taken.

lets say total displacement = 2x

and half the displacement will be x/2 for which the body travels with v1

and for another x/2 it travels with v2

so..... as we know [time = distance / velocity]

< v_{avg} > = $\frac{2x}{\frac{x}{v1}+\frac{x}{v2} }$

⇒ < v_{avg} > = $\frac{2 . v1 . v2}{v1+v2}$

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