Question

an athlete runs on a circular track of radius 25 m with a speed of 27 km per hour calculator time taken to complete 3.5 rounds how to calculate displacement at the end of 3.5rounds
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Answer 1

Given :-

Radius of track = 25 m

Velocity = 27 km/hr or,

7.5 m/s

To find :-

Displacement and distance covered in 3.5 round.

Answer:-

D = 549.5 m

S = 50 m

Solution :-

Circumference of circle = $2\pi r$

$C = 2 × 3.14 × 25$

$C = 157 m$

Now, Circumference of circle = one complete round

In 3.5 round the distance cover will be $D = 3 × C + \pi r$

$D = 3 × 157 + 3.14 × 25$

$D= 471 + 78.5$

$D=549.5$

Now, displacement covered in 3 round will be 0 because it comes to its starting point .

So, Displacement covered will be equal to diameter of track,

$S = 2 r$

$S = 2 × 25$

$S = 50 m$

hence, displacement is 50 m.