Question

the diameter of wheel of a car is 77cm . how many revolution will it make to travel 121km

Answer 1

Diameter of the wheel = 77 cm = 77 / 100000 Km = 0.00077 km.

So the circumference of the wheel = 2 x 22/7 x r = 22/7D = 22/7 x 0.00077 = 0.00242 Mts.

The distance travelled by car = 121 Kms.

So the number of revolution the wheel will take to travel 121 Km = 121 / Circumference of the wheel

= 121/0.00242 = 50000 nos.

Ans: 50000 Nos.

Answer 2

Given the diameter of the wheel = 77cm.

Then the radius will be r = d/2 = 77/2.

We know that circumference of the wheel = 2pir

                                                                       = 2 * 22/7 * 77/2

                                                                      = 242 cm.

We know that 1cm = 1/100 m 

242 cm = 242/100 = 2.42m.


Given that distance covered  = 121 km.

                                                 = 121000 m.


The total number of revolutions of the wheel = 121000/2.42

                                                                            = 50000.

The number of revolutions traveled = 50000.


Hope this helps!