A playground merry-go-round with a mass of 105 kg and a radius of 1.4m is rotating with an angular frequency of 0.42 rev/s. What is the magnitude of its angular velocity in radians per second, after 17kg child gets onto it by grabbing its outer edge?

Arunner is training for an upcoming marathon by running around a 100-m-diameter circular track at constant speed. let a coordinate system have its origin at the center of the circle with the x-axis pointing east and the y-axis north. the runner starts at (x, y) = (50 m, 0 m) and runs 2.5 times around the track in a clockwise direction.