Question

A car travels 1 kilometre distance in which each wheel makes 450 complete revolutions. Find the radius of the its wheels.

Answer 1

Given: Distance travelled = 1 km = 1000 m; number of revolutions = 450. Let r = radius of each wheel (m).

Step-wise calculation:

1. Circumference of wheel = 2πr.

2. Distance covered in 450 revolutions = 450 × 2πr.

3. Equate to 1000 m: 450 × 2πr = 1000.

4. Solve for r: r = `1000/(450 xx 2π) = 1000/(900π)`.

Using `π = 22/7`,

`r = (7 xx 1000)/(2 xx 22 xx 450)` 

= `7000/19800` 

= `35/99` ≈ 0.3535 m

Radius of each wheel = 0.3535 m = 35.35 cm.