Question

A body travels first one third distance with uniform speed u and next one third with speed of v and the next one third distance with average speed w. Find the average speed?

Answer 1

Let the total distance be x

case1
distance=x/3
spees=u
time=d/s=x/3u

case 2
distance=x/3
spees=v
time=x/3 v

case3
distance=`x/3
speed=w
time =x/3w

total distance =x

total time=x/3u+x/3v+x/3w
=( x÷3)(1÷u + 1÷v + 1÷w)

avg speed= total distance/total time taken

=x/[(x/3)(1÷u + 1÷v + 1÷w)]


avg speed=3/ [(1÷u) + (1÷v) + (1÷w)]

like if satisfied