Question

A car has to travel 0.121 km to reach from A to B. If the radius of the tyre is 7 cm. How many times will the tyre rotate while the car travels from A to B?

$(Use\pi =\frac{22}{7})$

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Answer 1

Circumference of tyre = Distance travelled in each rotation

$2\pi r=2\times \frac{22}{7}\times 7=44cm.$

Total distance covered = Number of rotations $\times$ Circumference of tyre

Number of rotations

$=\frac{0.121km}{44cm}=\frac{0.121\times 1000m}{44\times 0.01m}=275$