A wheel makes 4000 revolution is covering a distance of 60km. The radius of the wheel is :
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 2.39 m
A wheel makes 4000 revolution is covering a distance of 60 km
first change 60 km into metres so 60 × 1000 = 60000 m
In one revelution wheel will cover 60000/4000m = 15m
in order to make one revelution wheel have to covers its own circumference = 2πr
2 × 22/7 × r = 15
r = 105/44 = 2.39 m