PLEASE HELP and actually help plz The position of masses 4kg, 6kg, 7kg, 10kg ,and 3kg are (0,1), (4,2), (3,5), (5,6), and (-2,4) respectively. Where must you place a mass of 13kg if you want the center of mass to be at (-1,-3)?​

Electric charge is uniformly distributed inside a nonconducting sphere of radius 0.30 m. the electric field at a point p, which is 0.50 m from the center of the sphere, is 15,000 n/c and is directed radially outward. what is the maximum magnitude of the electric field due to this sphere

With i really need the correct answer!

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?