A girl ties a toy airplane to end of string, and swings it around her head. The plane's average angular speed is 2.4 rad/s. In what time interval will the plane move through an angular displacement for 3.8 rad?
So how do I get started?? :confused:

Remember rate times time equals distance? Well here you know the rate (2.4 radians/sec) and the distance (3.8 radians), so can you calculate the time? Perhaps what's confusing you is that the units are in radians, whereas you're used to seeing rate/time/distance problems in linear units like meters -- but you use the same technique. Hope this helps.