I found that pretty disturbing and would like to know what happened to the girls.
Have you ever noticed that as you move towards the center of a merry-go-round it speeds up? The converse is also true. I hope that as they were thrown from the center of the merry-go-round their speed decreased.
Still: a scooter is designed to spin a couple of adults, plus a 200 pound scooter, up to 35 mph. The kinetic energy of a scooter and two adults at 35mph is significant and the damage in a crash can be fatal. If the energy imparted to the merry-go-round was similar it could easily have killed the two girls.
Before I got my learners permit at the tender age of 15 & 1/2 we use to do the same thing with a buddy's Mini-Trail, except we' d spin one of those BIG diamond-plate steel jobs that was about 12 feet in diameter (Bellview Park). Could even shift into second if you were really good.
Small children would be flung 15 feet into the sand box. Teenagers about 10. After a while a long line would form to see who was next.
Your dynamics are screwed up.......the rotational speed is identical at various points along the disc,but the linear velocity increases the farther away from the center you are. Also the girl was propelled outward due to centripetal force....when tyhat force threw her,the only thing slowing her down was drag;when she hit the ground (9hopefully not something else) due to gravity her outward velocity was still pretty close to when she left the disc.......i hope the ground was soft
In the absence of an outside force, it will spin faster as you move to the center. This is due to conservation of (rotational) inertia. It's the same effect that figure skaters use to speed up their spins by moving their arms inwards.
As the merry-go-round in question was being spun by a moron on a scooter, it really wouldn't matter if they were in the middle or the outside once it got up to speed.
If you look carefully, there were two children in the center. All involved are very lucky either of the children did not egress into the scooter, or the leg of the person holding the scooter. IMHO, not funny at all.