Question

A 40.0-kg child running at 3.00 m/s suddenly jumps onto a stationary playground merry-go-round at a distance 1.50 m from the axis of rotation of the merry-go-round. The child is traveling tangential to the edge of the merry-go-round just before jumping on. The moment of inertia about its axis of rotation is 600 kg ? m2 and very little friction at its rotation axis. What is the angular speed of the merry-go-round just after the child has jumped onto it? A) 0.261 rad/s B) 0.788 rad/s C) 2.00 rad/s D) 3.14 rev/s E) 6.28 rev/s

Answer 1

Angular momentum is consumed during the Jump (40)(3)(1.5) = (600 + 40 times 1.50^2) w rightarrow 180 = (600 + 90) w rightarrow w = 180/690 = 0.261 rad/s w = 0.261 rad/ s