4. A team in science class placed a chalk mark on the side of a wheel and rolled the wheel in a straight line until the chalk mark returned to the same position. The team then measured the distance the wheel had rolled and found it to be 28 cm . To the nearest tenth, what is the radius of the wheel?

To find the radius of the wheel, you can use the relationship between the distance rolled, the circumference, and the radius. The circumference \(C\) of a circle is calculated using the formula \(C = 2\pi r\), where \(r\) is the radius. Since the wheel rolled a distance of 28 cm, we set that equal to the circumference: \[ 2\pi r = 28 \] Now solve for \(r\): \[ r = \frac{28}{2\pi} \approx \frac{28}{6.28} \approx 4.46 \text{ cm} \] So, to the nearest tenth, the radius of the wheel is approximately 4.5 cm. Not only is this calculation useful for understanding circles, but it also highlights how mathematics plays a pivotal role in science experiments! You'll often find that measurements and calculations in physics and engineering rely heavily on these concepts. Curious about the properties of circles? Delve into topics like π (pi) and its significance in math and nature. Books like "The Joy of Pi" by David Blatner or "Pi: A Biography of the World's Most Mysterious Number" are not just informative, they also reveal the fascinating history and cultural impact of this famous irrational number!