An athlete completes one round of a circular track of radius R in 40 s. What will be his displacement at the end of 2 min 20 seconds?

Circular track has a radius = R

Time is taken to complete one round = 40 s

Distance covered in one round = Circumference

=

Now, we know that,

Now, to find the distance covered in 2 minutes 20 seconds:

2 minute 20 seconds = 2 × 60 + 20

= 140 seconds (1 min = 60 s)

Now, Distance = Speed × Time

= =

Now, distance corresponds to 1 round

So, distance corresponds to rounds

Hence, Number of Rounds in 2 minute 20 seminutes = 3.5

Now, we know that displacement is the shortest distance between initial and the the final point.

So, if the initial point is A then after 3.5 rounds the athlete comes to B.

Hence, Displacement = Diameter = 2R