Question

A cyclist goes one round a circular track of diameter 105.in 5 minutes.calculate his speed .

Answer 1

The Diameter is 105m.
The perimeter of the circle = 2πR or πD

perimeter = π*105

Speed = Distance/ time
= 105*π / 5*60
= 1.099 m/s

Hope this helps.

Answer 2

Speed =distance /time

Here distance=2πr or πD

we are given D=105m

so distance=105π

time=5×60=300sec

so speed =105π/300
=105×3.14/300
=330/300
=1.1m/s