A 3.0-m-diameter merry-go-round with a mass of \(250 \mathrm{~kg}\) is spinning at \(20 \mathrm{rpm}\). John runs around the merry-go-round at \(5.0 \mathrm{~m} / \mathrm{s}\), in the same direction that it is turning, and jumps onto the outer edge. John's mass is \(30 \mathrm{~kg}\). What is the merry-goround's angular speed, in rpm, after John jumps on?