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, and (b) average velocity, of the boy.

Answer 1

a)    Distance travelled is the length of the actual path covered.
Total distance covered in going and coming back :
= (20 + 20) m
= 40 m
Total time taken, = (25 + 25) s
= 50 s
So, we can calculate average speed as :
`"Average Speed" = "Total distance travelled"/"Time"`
Average speed for the entire journey ; 
= `40/50`
= 0.8 m/s