Question

Rahul ,an athlete Completes one round of a circular track of a diameter 200m in 90s.What will be the distance covered at the end of 1mins 10

Answer 1

Distance covered by Rahul = Circumference of a circle

{ Circumference of circle = 2πr }

Given diameter is 200 m. So, the radius is equal to half of the diameter i.e. 100 m.

Also, he completes one round of a circular track of a diameter 200 m in the 90 sec. So, time is 90 sec.

Distance covered by Rahul in one round (in 90 sec) = 2 × 22/7 × 100 = 628.57 m

Distance covered by Rahul in 1 sec = 628.57/90 = 6.98 m

We have to find the distance covered at the end of 1 min 10 sec.

{ 1 min 10 sec = 60 sec + 10 sec = 70 sec }

So, Distance covered in 70 sec = 6.98 × 70 = 488.60 m

Answer 2

Given :-

$\texttt{Rahul completes a round in a circular track of diameter}\\\texttt{200 m in 90 s.}$

To find :-

$\texttt{The distance that will be covered at the end of 1 min 10 s.}$

Solution :-

$\texttt{Distance of the track = 2}\pi \texttt{r}$

$\tt{\implies Distance=2*\pi*\frac{200}{2} }\\\\\tt{\implies Distance=200*\frac{22}{7} }\\\\\bold{\tt{\implies Distance=628.57\ m}}$

$\texttt{Time taken by Rahul to move 628.57 m = 90 s.}\\\\\texttt{So, distance covered by Rahul in 1 s = 628.57/90 = 6.98 m}$

∴ $\tt{Distance\ covered\ in\ 1\ min\ 10\ s=Distance\ covered\ in\ 70\ s.}$

$\texttt{Now, distance covered in 70 s = 70*distance covered }\\\texttt{in 1 s.}\\\tt{Distance\ covered\ in\ 70\ s = 70*6.98}\\\\\text{\boxed{\implies Distance\ covered\ in\ 70\ s = 488.6\ m}}$