A merry-go-round disk with a rotational inertia of Id I
d
about its center spins around its center axle with an initial angular velocity of ω0
ω
0
. A child is standing near the edge of the merry-go-round, as shown in Figure 1. The child’s rotational inertia about the center of the disk when near the edge is I0
I
0
. As the merry-go-round spins, the child moves closer to the center, as shown in Figure 2, until the disk rotates with an angular velocity of ω1
ω
1
. Which of the following equations could a student use to determine the rotational inertia Is
I
s
of the child-merry-go-round system about the center axle immediately after the child has moved to the location shown in Figure 2? Justify your selection

Amass m = 74 kg slides on a frictionless track that has a drop, followed by a loop-the-loop with radius r = 18.4 m and finally a flat straight section at the same height as the center of the loop (18.4 m off the ground). since the mass would not make it around the loop if released from the height of the top of the loop (do you know why? ) it must be released above the top of the loop-the-loop height. (assume the mass never leaves the smooth track at any point on its path.) 1. what is the minimum speed the block must have at the top of the loop to make it around the loop-the-loop without leaving the track? 2. what height above the ground must the mass begin to make it around the loop-the-loop? 3. if the mass has just enough speed to make it around the loop without leaving the track, what will its speed be at the bottom of the loop? 4. if the mass has just enough speed to make it around the loop without leaving the track, what is its speed at the final flat level (18.4 m off the ground)? 5. now a spring with spring constant k = 15600 n/m is used on the final flat surface to stop the mass. how far does the spring compress?