Question

a body goes from A to B with a velocity of 40 m/s and comes back from B to A with the velocity of 60 m/s .what is the (i) average velocity during the whole journey (ii) average speed during the whole journey

Answer 1

1) Here the average velocity would be zero as the net displacement would be zero, the body being at it initial starting point 'A' after the journey.

2) For average speed

s = d/ t

therefore,

40 = d/ t1
t1 = d/ 40

Again 60 = d/ t2

therefore,

t2 = d/ 60

now averege speed = total distance covered/ total time taken

= { 2d }/ { (d/40) + (d/ 60)}

= 48 m/s ANS