after how many complete rotations will a bicycle wheel with a diameter of 65cm cover a distance of 2km
2000000cm / (65π cm/rev) = 979.4 rev
To find out the number of complete rotations a bicycle wheel with a diameter of 65cm needs to cover a distance of 2km, you can follow these steps:
1. Calculate the circumference of the wheel: The circumference of a circle is given by the formula C = πd, where d is the diameter of the circle. In this case, the diameter is 65cm, so the circumference would be C = π(65cm).
2. Convert the circumference to kilometers: Since the distance you want to cover is given in kilometers, you need to convert the circumference of the wheel from centimeters to kilometers. Remember that there are 100,000 centimeters in a kilometer.
To convert the circumference from centimeters to kilometers, divide the circumference by 100,000: C (km) = C (cm) / 100,000.
3. Calculate the number of rotations: Divide the distance you want to cover (2km) by the circumference of the wheel in kilometers (C (km)). This will give you the number of rotations needed to cover the desired distance.
Number of rotations = Distance / C (km).
Let's perform the calculations:
1. Circumference of the wheel:
C = πd
C = π(65cm)
C ≈ 204.2cm
2. Convert the circumference to kilometers:
C (km) = C (cm) / 100,000
C (km) ≈ 0.002042km
3. Calculate the number of rotations:
Number of rotations = Distance / C (km)
Number of rotations = 2km / 0.002042km
Number of rotations ≈ 979.7
Therefore, a bicycle wheel with a diameter of 65cm will cover a distance of 2km in approximately 979.7 complete rotations.