An object is traveling around a circle with a radius of 20 meters. If in 10 seconds a central angle of 1/5 radian is swept out, what is the linear speed of the object?

The linear speed of the object is the ratio between the measure of the arc it had traveled and the time. For the length of the arc,

2π x (20 m) x (0.2 rad / 2π rad) = 4 meters

Divide this by the time, 10 s. Thus, the linear speed is equal to 0.4 m/s.