Question

A boy walks from his classroom to the bookshop along a straight corridor towards North.
He covers a distance of 20 m in 25 seconds to reach the bookshop. After buying a book,he travels the same distance in the same time to reach back in the classroom. Find:
(a) average speed
(b) average velocity
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Answer 1

Answer:

Given :

A boy walks from his classroom to the bookshop along a straight corridor towards North. He covers a distance of 20 m in 25 seconds to reach the bookshop

Distance from classroom to book shop =20m

time =25sec

After buying a book, he travels the same distance in the same time to reach back in the classroom

distance=20m

time=25 sec

I) Average speed = Total distance / Total Time

=(20+20)/(25+25)

=40/50

=0.8 m/s

II) Average Velocity= Displacement / Total time 

As displacement is the shortest path between source and destination.

Here Displacement= 0  because child travels 20m forward and travels 20 m backwards .

Displacement=20-20=0

Hence Average velocity = 0/50 = 0m/s

Answer 2

Explanation:

◆◆◆◆◆Hi Mate◆◆◆◆◆

(a) Total distance covered in going to the bookshop and coming back to the classroom : 20+20= 40m.

Total time taken = 25+25=50s

Average speed=Total Distance/Total Time =40/50= 0.8m/s.

(b) Average velocity=Total Displacement/Total Time=0/50=0m/s.

I hope it's help you.....