Question

a body move half of its journey with speed of 20 m/s and other half with 30m/s find average velocity of body for whole journey

Answer 1

a body moves half of its journey with speed of 20m/s and other half with 30m/s . we have to find average velocity of body for whole journey.

Let displacement between starting and finishing point of journey is L.

half displacement is covered by 20m/s
so, time taken to cover L/2 distance , t = L/2(20) = L/40

and time taken to cover by other half displacement, t' = L/2(30) = L/60

now, average velocity = total displacement/total time taken
= L/(t + t')
= L/(L/40 + L/60)
= 40 × 60/100
= 2400/100
= 24 m/s