If the wheel of a bicycle makes 160 revolutions in travelling 1.8 km, then what is its radius (in m)?
Answer & explanation
Correct answer: option 1
We know that,
Circumference of circle = 2πr
Given,
Revolutions = 160
Distance covered = 1.8km
160 revolutions = 1.8 km = 1800 m
1 revolution = \(\frac{1800}{160}\) = \(\frac{45}{4}\)
We also know that, Circumference of wheel = 1 revolution
= 2πr = \(\frac{45}{4}\)
= r = \(\frac{45}{4 × 2π }\)
= r = \(\frac{45}{8π }\)