Aheavy (2.0 kg) point-like object rests 2.0m from the center of a rough turntable as the turntable rotates. the period of the turntable's rotation is 5.0 seconds. the coefficient of kinetic friction between the object and turntable is 0.50, while the coefficient of static friction is 0.80. what is the magnitude of the force of friction acting on the object?

When a charged balloon sticks to a wall, the downward gravitational force is balanced by an upward static friction force. the normal force is provided by the electrical attraction between the charged balloon and the equal but oppositely charged polarization induced in the wall's molecules. if the mass of a balloon is 1.2 g, its coefficient of static friction with the wall is 0.71, and the average distance between the opposite charges is 0.80 mm, what minimum amount of charge must be placed on the balloon in order for it to stick to the wall? express your answer to two significant figures and include appropriate units.