Question

diameter of the wheel of a bus is 140 cm how many revolutions per minute must A wheel make in order to move at speed of 66 km per hour ​

Answer 1

Answer:

$By:-Aryan~Gupta$

The no of revolution per minute would be 250

Soloutiin:~1 revolution = circumference of the circle =\pi\times d=π×d 

                                                                       =3.14\times 140=3.14×140

                                                                       =439.6=439.6 cm

Revolution in 6666 km =\dfrac{6600000}{439.6}=439.66600000

                                   =15013.6=15013.6 per hr

                                   =\dfrac{15013.6}{60}=6015013.6 per min

                                   =\dfrac{15013.6}{60}=6015013.6 per min

                                   =250.22=250.22 per min

                                   \approx 250≈ 250 per min

Answer 2

$\huge{\fbox{\fbox{\bigstar{\underline{\red{Answer}}}}}}$

↪Number of revolutions per min is 250.

$\bf{\huge{\underline{\boxed{\bf{\pink{Given\::}}}}}}$ ↪ The diameter of the driving wheel of a bus is 140 cm.

$\bf{\huge{\underline{\boxed{\bf{\pink{To\:find\::}}}}}}$ ↪How many revolutions per minute must the wheel make in order to keep a speed of 66 km per hour?

$\huge{\fbox{\fbox{\bigstar{\underline{\red{Solution:}}}}}}$

↪Diameter of the wheel = 140 cm

↪Radius of the wheel is = 70 cm =0.70 m

↪The circumference of the wheel is ⇒

↪C ⇒2×22×0.70m

7

↪Distance to be covered in 1 min. is ⇒

↪D ⇒(66×1000)m

60

↪D ⇒1100m

↪Circumference = No.of revolutions * Distance covered

↪n ⇒ C

D

↪n⇒1100

4.4

↪n⇒250

↪Number of revolutions per min is → 250.....