Question

A cyclist goes once round a circular track of diameter 105 m in 5 minutes.
Calculate his speed ?

Answer 1

[tex]Speed = \frac{Distance}{Time} Distance = circumference of the circular track [/tex]

Circumference of the circular track = 2πr = 22/7×105 = 330m

Time = 5 minutes = 5 × 60 = 300s 

Speed = $\frac{330}{300} = \frac{11}{10} =1.1 m/s$

Answer 2

If a cyclist goes once round a circular track, the distance he covers is actually the circumference of the the circular path:

Circumference= 2πr

Given diameter= 105 m
radius=diameter/2 = 105/2 = 52.5
Circumference= 2×3.14×52.5
                       =329.7 ≈ 330 m

So,
Distance=330 m
time=5 min=5×60=300 s

Speed= Distance/Time 
           = 330/300= 1.1 m/s