A merry-go-round has a radius of 2.0 m and a moment of inertia of 300 kgm2 . A boy of mass 50 kg runs tangent to the rim at 4.0 m/s and jumps on. If the merry-go-round is initially at rest, what is the angular velocity after the boy jumps on

Sorry i don’t know what to do

Not what goes around on earth but the universe too.

The chemical reactions lab we did is typically called a "copper plating lab,  because the acid solution cleaned the pennies and made the copper look shinier;   the acid solution cleaned the paperclips and made them look like pennies;   &   the copper from the pennies was removed, and then added to the paperclips.