Question

An automobile wheel has a diameter of 35cm .how many revolutions will it make to cover a distance of 11 kilometers?

Answer 1

Given: diameter = 35 cm
radius = 35/2
distance covered = 11 km
= 11 × 1000 × 100 cm
=11,00,000 cm

Let the number of revolutions taken be y .And the wheel is in the form a circle so it will move on its boundary or perimeter.

Perimeter of a circle= 2πr

Then the number of revolutions will be-
2πr×y
And it is given that the value of 2πry is 11,00,000 cm .

2×π×r×y = 11,00,000 cm
2×22/7×35/2×y = 11,00,000 cm
2×11×5×y = 11,00,000 cm
110y = 11,00,000 cm
y = 11,00,000/110
y = 10,000

Hence the number of revolutions taken to cover 11 km is 10,000.