A30-kg child starts at the center of a playground merry-go-round that has a radius of 2.1 m and rotational inertia of 500 kg⋅m2 and walks out to the edge. the merry-go-round has a rotational speed of 0.20 s−1 when she is at the center?

Explanation:

As we know that there is no torque on the system of merry go round

so the angular momentum will remain conserved

so here we have

so we will have

now from above formula

whichever one it is, it's definitely not one that you included on the list you provided.

in simple terms, the principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or the density of the fluid multiplied by the submerged volume times the gravitational acceleration, g. this is also known as upthrust.