The diameter of the driving wheel of a bus is 140 cm. How many revolut

1.	The diameter of the driving wheel of a bus is 140 cm. How many revolutions per minute must the wheel make in order to keep a speed of 66 km per hour?
Answer» Given diameter of the wheel = 140 cm Desired speed of the bus = 66 km/hr Distance covered by the wheel in 1 revolution = Circumference of the wheel Circumference of the wheel = πd C = 22/7 × 140 C = 440 cm Now, the desired speed of the bus = 66 km/hr = 66 × 1000 × (100/60) = 110000 cm/min Number of revolution per minute = 110000/440 = 250 Therefore, the bus must make 250 revolutions per minute to keep the speed at 66 km/hr.

The diameter of the driving wheel of a bus is 140 cm. How many revolutions per minute must the wheel make in order to keep a speed of 66 km per hour?

Answer»

Given diameter of the wheel = 140 cm

Desired speed of the bus = 66 km/hr

Distance covered by the wheel in 1 revolution = Circumference of the wheel

Circumference of the wheel = πd

C = 22/7 × 140

C = 440 cm

Now, the desired speed of the bus = 66 km/hr = 66 × 1000 × (100/60) = 110000 cm/min

Number of revolution per minute = 110000/440

= 250

Therefore, the bus must make 250 revolutions per minute to keep the speed at 66 km/hr.