Question

A wheel of radius 10 inches is rotating 20°/sec. What is the linear speed in in/sec and the angular speed in RPM? (Round your answers to three decimal places) ____ in/sec ____ RPM What is the angular speed in radians/sec? ____ radians/sec

Answer 1

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Answer:

a) 3.491 in/s

b) 3.333 RPM

c) 0.349 rad/s

Explanation:

We know the arc length for a given radius and angle is ...

s = rθ

so the linear speed along the arc is ...

s' = rθ' = (10 in)(20π/180 rad/s) = 10π/9 in/s ≈ 3.491 in/s

__

The rotation rate of 20°/s is an angular velocity of ...

(20°/s)(60s/min)(1 rev/360°) = 3.333 RPM

__

In the first part, we found the angular speed to be π/9 radians/sec. That's about ...

π/9 rad/s ≈ 0.349 rad/s