A4.0-m-diameter playground merry-go-round, with a moment of inertia of

500kg? m2 is freely rotating with an angular velocity of 2.0rad/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. how fast was ryan running when he jumped on?

ms⁻¹

Explanation:

= diameter of merry-go-round = 4 m

= radius of merry-go-round = =   = 2 m

= moment of inertia = 500 kgm²

= angular velocity of merry-go-round before ryan jumps = 2.0 rad/s

= angular velocity of merry-go-round after ryan jumps = 0 rad/s

= velocity of ryan before jumping onto the merry-go-round

= mass of ryan = 70 kg

Using conservation of angular momentum

ms⁻¹

I'm pretty sure that the answer is B! Hope this helps!