A wheel has diameter 84 cm . Find how many complete revolutions must it make to cover 3.168 km.
converting everything to cm, we have
84π*n = 3168*100
n = 316800/(84π) = 1200.48
To find the number of complete revolutions the wheel must make to cover a certain distance, we need to relate the distance to the circumference of the wheel.
The circumference of a wheel can be found using the formula: C = πd, where C is the circumference and d is the diameter of the wheel.
In this case, the diameter of the wheel is given as 84 cm, so we can calculate the circumference using the formula: C = π * 84 cm.
To find the number of complete revolutions needed to cover a distance of 3.168 km, we need to convert the distance to centimeters since the circumference of the wheel is given in centimeters.
Converting 3.168 km to centimeters, we have: 3.168 km * 100,000 cm/km = 316,800 cm.
Now, we can divide the distance by the circumference of one revolution to find the number of complete revolutions:
Number of revolutions = Distance / Circumference
Number of revolutions = 316,800 cm / (π * 84 cm)
Using the value of π as approximately 3.14, we can calculate the number of complete revolutions:
Number of revolutions ≈ 316,800 cm / (3.14 * 84 cm)
Number of revolutions ≈ 1200
Therefore, the wheel must make approximately 1200 complete revolutions to cover a distance of 3.168 km.