Question

An athlete completes one round of a circular track of diameter
200 m in 40 s. What will be the distance covered and the
displacement at the end of 2 minutes 20 s?
ad of a straight​

Answer 1

Answer:

The diameter of the circular track is given as 200 m. That is, 2r=200 m.

From this radius is calculated as Radius, r = 100 m.

In 40 sec the athlete complete one round. So, in 2 mins and 20 secs, that is, 140 sec the athlete will complete = 140 / 40 = 3.5 (three and a half) rounds.

One round is considered as the circumference of the circular track.

The distance covered in 140 sec = 2πr×3.5=2×3.14×100×3.5=2200 m.

For each complete round the displacement is zero. Therefore for 3 complete rounds, the displacement will be zero.

At the end of his motion, the athlete will be in the diametrically opposite position. That is, displacement = diameter = 200 m.

Hence, the distance covered is 2200 m and the displacement is 200 m.

Answer 2

Answer:

AN ATHLETE COMPLETES ONE ROUND OF A CIRCULAR TRACK OF DIAMETER 200 M IN 40 SECONDS,

RADIUS =DIAMETER/2=200/2=100M

DISTANCE COVERED =

$2 \times \pi \times r$

let's take value of pi to be 22/7,

$2 \times \frac{22}{7} \times 100 = \frac{4400}{7}$

SO IN 40 SECONDS HE COMPLETES 4400/7 M

NOW IN 2 MINS 20 S=140 SECONDS HE COVERED,

IN 1 SECOND =4400/7×1/40=4400/280

IN 140 SECONDS=4400/280×140=4400/2=2200 M

DISPLACEMENT WILL BE 140/4=3 .5

That is the diameter 200 m wiil be the DISPLACEMENT..