Question

A bicycle makes 5000 revolutions while travelling 11 km. What is the radius of the wheel?

Answer 1

Answer:

Distance covered in 5000 rev. ---> 11km

Distance covered in 1 rev. ----> 11/5000 = 0.0022 km = 2.2m

Since in one revolution, the whole of the tyre is contact with the ground,

Therefore, 2.2 = 2πr

πr = 1.1

r = 1.1/π= 0.35m (approx.)

Answer 2

Answer:

Radius of wheel = 3.5 m

Step-by-step explanation:

Distance Covered = 11 km = 11000 m

Number of revolutions of wheel of the cycle = 5000

So, Circumference of wheel = Distance Covered/Number of revolutions

             C = 11000/5000

             C = 2.2 m²

We know that, Circumference = 2πr

                        So,      C = 2 × 22/7 × r

                                   2.2 = 2 × 22/7 × r

                                    r = (2.2×7)/(22×2)

                                    r = 3.5 m