Question

A runner Travels 1.5 laps around a circular track in a time of 50 sec. the diameter of track is 40 m and circumference is 126 metre find the average speed of the runner in meter/sec

Answer 1

speed=distance÷time. so circumference of 1 complete round =126
so 1.5 round= 126+1/2×126=189. time is 50sec .
hence speed =189÷50=3.78m/s

Answer 2

The average speed of the runner is 3.78 m/s.

Explanation:

The diameter of the track, d = 40 m

Radius, r = 20 m

A runner Travels 1.5 laps around a circular track in a time of 50 sec.

The circumference of the circular track is, C = 126 m

The total distance covered by the runner is:

$d=1.5\times 126=189\ m$

Let v is the average speed of the runner. It is given by total distance covered divided by total time taken. It is given by :

$v=\dfrac{v}{t}\\\\v=\dfrac{189\ m}{50\ s}\\\\v=3.78\ m/s$

So, the average speed of the runner is 3.78 m/s.

Learn more,

Average speed

https://brainly.in/question/7248102