Question

a particle is moving along a circle such that it complete one revolution in 40sec.in2 min 20 sec the ratio displacement and distance is

Answer 1

ʜᴇʟʟᴏ ᴍᴀᴛᴇ!

Let the object at point A

As given, object covers whole park in 40s

Now, 2 min 20s = 2*60s + 20s
= 140s

In 40s the object takes = 1 round.
In 140s the object takes = 140/40 or 3.5 rounds.

Now, take 1 round from A, and similarly take 2 rounds more.

Now, take a half round and you will end you journey at B

So, displacement = diameter of circle
= 2r

Distance = circumference

Circumference = 2πr

As body took 3.5 rounds so,

= 3.5 ( 2* 22/7 * r )
= 3.5 * 44/7 * r
= 0.5*44r or 22r

Now, ratio of displacement and distance

= 2r / 22r = 1/11 or 1 : 11

Hope it helps