Question

Q.11A particle travels first half of the total distance with constant speed v1 and second half with
constant speed v2 . Find the(i) average speed (ii)average velocity during the complete journey.

Answer 1

Answer:

particle travels in a circular path , let us consider radius of its locus is r

So , when the particle goes half the circle following the circumference of the circle , the distance traversed is 2πr ×1/2 unit as circumference =2πr

So distance = πr unit

But linear distance between its starting point and end point is the diameter .

So, the displacement of the particle = 2r unit

If average speed of the particle is V and the distance is πr

So, time taken = πr/V

So, average speed again is conversely remaining V

So , the average velocity = displacement /time = 2r/(πr/V)= 2r.V/πr = 2V/π (Ans.)