12. Julie has a mass of 49 kg. What is her potential energy when standing on the 6 meter diving board? (She is 6 meters above the water.) Julie jumps off the diving board. a. What is her kinetic energy just before she hits the water?

b. What is Julie’s speed just as she hits the water?

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?