The diameter of the wheel of a car is 84 cm and the speed of a car is 72 km/h. How many revolutions made by the wheel in 11 minutes?
The diameter of the wheel of a car is 84 cm and the speed of a car is 72 km/h. How many revolutions made by the wheel in 11 minutes?
گاڑی کے پہیے کا قطر 84 سینٹی میٹر اور گاڑی کی رفتار 72 کلومیٹر ہےوہیل نے 11 منٹ میں کتنے چکر لگائے؟
Explanation
Diameter of car wheel is 84 cm
Circumference of the wheel = 2*pi*r
= 2*22*.42/7
= 2.64 meter
Speed of the car is 72 kmph
Speed in m/sec is 72*5/18 = 20 m/sec
Distance covered in 11 minutes = 20*11*60 = 13200 meter
Number of revolutions in 11 minutes = distance covered in 11 minutes / circumference of the wheel
= 13200/2.64
= 5000 revolutions