Can anybody helppp me with this Which is an example of a physical change?

cake baking

gasoline combusting

salt dissolving

iron rusting

Plss anybody know how to do this? ? i need the answers from a through d

Aperson stands on a platform, initially at rest, that can rotate freely without friction. the moment of inertia of the person plus the platform is ip. the person holds a spinning bicycle wheel with its axis horizontal. the wheel has moment of inertia iw and angular velocity ωw. take the ωw direction counterclockwise when viewed from above. part a what will be the angular velocity ωp of the platform if the person moves the axis of the wheel so that it points vertically upward?

This is the substance(s) formed in a chemical reaction.