What is the circumference of a truck tire if it rotates at 400 revolutions per minute when the motorcycle is traveling 72 kilometers per hour?

Question

What is the circumference of a truck tire if it rotates at 400 revolutions per minute when the motorcycle is traveling 72 kilometers per hour?

Answer 1

circonference = 1rev.(one revolution)

72km in 1h convert to 72000m in 60min convert to 1200m in 1min.

1min=400rev

                     >⇒ 400rev=1200m ⇒ 1rev=1200m/400

1min=1200m

 

 

1rev=3m

Answer 2

(72 km/hr)/(60 min/hr) = 1.2 km/minute

 

(1.2 km/min)/(400 rev/min) =

(1200 m/min)/(400 rev/min) =

3 m/rev

 

The tire rotates 3 meters per revolution

so that is the circumference of the tire.