Question

A bicycle wheel makes 500 revolution in 1 km . Find the diameter of the wheel.

Answer 1

total distance covered = circumference×no. of revolution
1km=2pie r × 500
1km=2×22/7×r×500
r=1×7/2×22×500
d =2r
=2×7/2×22×500
=7/11000km
=7/11m

Answer 2

Distance covered in 1 revolution = circumference of a circle = 2πr
Distance covered in 500 revolutions = 500 × 2πr = 1000πr m²
distance covered in 500 revolutions = 1 k m = 1000m

1000πr m² = 1000m
1000 × 22 / 7 × r = 1000
r = [1000 × 7 ] ÷ [1000 × 22 ]
r = 7 /22 m

diameter = 2r
= 7 / 22 × 2
= 7 / 11 m