A 40-m-diameter playground merry-go-round with a moment of

Question

Solve the following problem given below:

Problem: A 4.0-m-diameter playground merry-go-round, with a moment of inertia of 350kg•m² is freely rotating with an angular velocity of 2.5rad/s. Ryan, whose mass is 70kg, runs on the ground around the outer edge of the merry-go-round in the opposite direction to its rotation. Still moving, he jumps directly onto the rim of the merry-go-round, bringing it (and himself) to a halt.

Part A- How fast was Ryan running when he jumped on?

Write your solution in appropriate format and give references.