An engine wheel has circumference 300 cm (3 m) and makes 10 revolutions in 6 seconds. What is the linear speed of the wheel in km/h?

Introduction / Context:
Linear speed = (revolutions per time) * circumference. Convert the resulting m/s to km/h by multiplying by 3.6.

Given Data / Assumptions:

• Circumference = 300 cm = 3 m.
• 10 revolutions in 6 s.

Concept / Approach:
Distance traveled in 6 s = 10 * 3 = 30 m. So speed = 30/6 = 5 m/s. Convert to km/h: 5 * 3.6 = 18 km/h.

Step-by-Step Solution:

Verification / Alternative check:
Using unit factors: (5 m/s)*(18/5) = 18 km/h.

Why Other Options Are Wrong:
20/27/36 km/h require different revolution counts or circumference.

Common Pitfalls:
Forgetting to convert cm to m or m/s to km/h.

Final Answer:
18