if the wheel of the car with 80cm diameter makes 360 revolution per minute find the speed of the car in km/hr
Answers
The speed of the car in km/hr = 54.3 km/hr.
1) It is given that the wheel of the car has a diameter (d) of 80 cm.
Therefore, distance that the wheel covers in 1 revolution = The circumference of the wheel = π×d = (π×80) cm = 251.33 cm.
2) Next, the wheel makes 360 revolutions per minute.
Therefore, distance covered in one minute = distance covered in 360 revolution = 360 × distance covered in one revolution = (360 × 251.33) cm = 90477.87 cm.
3) Thus, the car covers a distance of 90477.87 cm per minute.
But, we need to answer in km/hr.
Therefore, distance covered (in km) = 90477.87/100000 = 0.905 km.
This distance is covered in 1 min.
Since 1 hr = 60 mins, therefore, total distance covered in 1 hr = 60 × distance covered (in km) in 1 minute = 60 × 0.905 = 54.3 km/hr.