Question

a boy Travels distance towards north with speed V1 then takes a right turn towards east to Travels a distance D with speed V2 then find average velocity of the entire journey​

Answer 1

average velocity for the above mentioned problem is( v1+v2)/2

Answer 2

Answer:

$V_{avg}=\sqrt2\dfrac{V_1V_2}{V_1+V_2}$

Explanation:

Boy travel distance D in north and east direction.

So the total distance

$S=\sqrt{D^2+D^2}$

$S=D\sqrt{2}$

We know that

Total distance = Average speed x Total time

When he travel in north

D= V₁ t₁

t₁=D / V₁

When he travel in east direction

D= V₂ t₂

t₂ =D/V₂

Total time =  t₁ + t₂

Total time = D / V₁ + D/V₂

Total distance $S=D\sqrt{2}$

Total distance = Average speed x Total time

$D\sqrt{2}=\left(\dfrac{D}{V_1}+\dfrac{D}{V_2}\right)V_{avg}$

$V_{avg}=\sqrt2\dfrac{V_1V_2}{V_1+V_2}$