Question

19. The diameter of the wheel of a car is 77 cm. How many revolutions will it make to travel
121 km?
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Answer 1

Let the number of revolutions be x.

x* Circumference of wheel= Area covered

x*2Πr=121 km

x*2*22/7*77/2=12100000cm

x*44*77/14=12100000

x*3388/14=12100000

x*242=12100000

x=50000

Hence, the wheel of the car has to take 50,000 revolutions to cover an area of 121 km.

Answer 2

Answer:

Diameter of car =77cm

Distance =121km

Step-by-step explanation:

R=77/2

Speed =D/T

121/60

now, Area of circle =πr^2

=22/7*77/2*77/2

=4658.5

Hence, 4658 revolutions will make it to travel 121km