Question

the diameter of a circle wheel is 21 cm how many revolutions within make it travel 198 km

Answer 1

Answer:

Step-by-step explanation:

Radius= 21/2cm.

Circumference of circle= 2πr.

2*22/7*21/2cm.

=66cm.

no.of revolution

=198000/66.

=3000

Answer 2

Given: d=21cm
so, r=21/2

circumference of circle =2πr
=2*22/7*21/2
=66cm sq.

revolution takes = distance/circumference of circle
distance=198*100000cm
=19800000

revolution takes=19800000/66

=3000(approx)