Question

A boy goes from A to B with a velocity of
20 m/min and comes back from B to A with a
velocity of 30 m/min. The average velocity of the
boy during the whole journey is​

Answer 1

Answer:

0

Explanation:

Average velocity

As net displacement will be zero then average velocity will be also zero.

Average speed

We know,

Speed = distance/time or s = d/t

Then,

20 = d/t1

t1 = d/20

And,

30 = d/t2

t2 = d/30

Average speed = total distance/total time

= [2d]/[(d/20) + (d/30)]

= 24 m/s

Answer 2

Given,

Velocity of boy from A to B=20m/min

From B to A=30m/min

To Find,

The average velocity of the boy.

Solution,

As its net displacement will be zero then average velocity will be also zero.

Average speed of the boy will be

We know,

Speed = distance/time or s = d/t

Then,

20 = d/t1,

t1 = d/20

And,

30 = d/t2

t2 = d/30

Average speed = total distance/total time

= (2d)/{(d/20) + (d/30)}

= 24 m/s

Hence, the average velocity of the boy during the whole journey is 24m/s.