Explain which of the following has more inertia and why: a 200 lb wrestler sitting on a mat or a baseball flying through the air at 55 mi/hr.

Inertia is the property of mass and as per the definition of inertia we can say that object will continue its state of motion and resist any change in its state of motion due to inertia

Inertia is only the property of mass and no other physical quantity can change the inertia of object

So it is directly proportional to the mass of the object

So if object has more mass then it will have more inertia

in this given example we have to compare the inertia of a 200lb wrestler and a baseball

So here the speed of baseball is of no use as inertia can not be determined by speed of the ball

Since here mass of the wrestler is more so his inertia will be more than the inertia of baseball