A container consists of two vertical cylindrical columns of different diameter connected by a narrow horizontal section, as shown in the figure. The open faces of the two columns are closed by very light plates that can move up and down without friction. The fube diameter at A is 35.0 cm and at B is 10.2 cm. This container is filled with oil of density 0.820 g/cm\"3. If a 200 kg object is placed on the larger plate at A, how much mass should be placed on the smaller plate at B to balance it? The speed of a 2 kg mass on a spring is 5 m/s as it passes through its equilibrium position. What is its frequency if the amplitude is 2.5 m? Answer: 1/3 Hz