Question

The diameter of a wheel of a car is 30cm. If the car travels at an average speed of 13.2m/s, find the number of revolutions made by the wheel per hour, giving your answer correct to the nearest whole number.

Answer 1

Answer:

Approximately $50420$ revolutions (rounded to the nearest whole number.)

Step-by-step explanation:

Convert the diameter of this wheel to meters: $d = 30\; \rm cm = 0.30\; \rm m$.

Circumference of this wheel:

$\pi \, d = \pi \times 0.30\; \rm m \approx 0.942\; \rm m$.

Distance travelled in one hour:

$\begin{aligned}v \cdot t &= 13.2 \; \rm m \cdot s^{-1} \times 3600\; \rm s \\ &= 47520\; \rm m\end{aligned}$.

Number of revolutions required for covering that distance:

$\displaystyle \frac{47520\; \rm m}{(\pi \times 0.30\; \rm m)} \approx 50420$.