Playground/merrygo round problem. Rotational kinematics

[iknowsigularity]

Homework Statement

In a playground there is a small merry-go-round of radius 1.20 m and mass 220 kg. The radius of gyration is 91.0 cm. A child of mass 44.0 kg runs at a speed of 3.00 m/s tangent to the rim of the merry-go-round when it is at rest and then jumps on. Neglect friction between the bearings and the shaft of the merry-go-round and find the angular speed of the merry-go-round and child.

I have no idea how to go about starting this, so I'm not looking for an answer just perhaps what equation I should be using. thanks for any help!

 

[gneill]

You need to state what you know and what the results are of your researching the problem. You can't have absolutely no idea if this is part of a course assignment. What equations pertain to the type of motion involved? What type of interaction is occurring?

 

[iknowsigularity]

You need to state what you know and what the results are of your researching the problem. You can't have absolutely no idea if this is part of a course assignment. What equations pertain to the type of motion involved? What type of interaction is occurring?

I assume possibly the conservation of angular momentum? and maybe you take the tangential speed of the child and transform it to angular speed?

 

[gneill]

I assume possibly the conservation of angular momentum? and maybe you take the tangential speed of the child and transform it to angular speed?

Okay, start there. Clearly there's a collision taking place (what type, elastic or inelastic?). What information will you need to know to handle a collision problem? (Think of a linear collision problem and what you'd want to know for that scenario. What are the angular motion analogs to those things?)

 

[iknowsigularity]

Okay, start there. Clearly there's a collision taking place (what type, elastic or inelastic?). What information will you need to know to handle a collision problem? (Think of a linear collision problem and what you'd want to know for that scenario. What are the angular motion analogs to those things?)

so would perhaps the conservation of kinetic energy formula work?

Okay, start there. Clearly there's a collision taking place (what type, elastic or inelastic?). What information will you need to know to handle a collision problem? (Think of a linear collision problem and what you'd want to know for that scenario. What are the angular motion analogs to those things?)

or actually its the conservation of angular momentum so (moment of inertia)(angular speed) intial = (moment of inertia)(angular speed) final?

 

[gneill]

or actually its the conservation of angular momentum so (moment of inertia)(angular speed) intial = (moment of inertia)(angular speed) final?

Yes.