# Frequency of oscillation

1. Aug 30, 2012

### Ry122

In this problem I guess I would first need to model the position of the cylinder with an equation and from that solve for the natural frequency. But how do I go about doing this when the object's default position is stationary?

2. Aug 30, 2012

### gabbagabbahey

What is the force on the cylinder when it is displaced from its equilibrium position by a distance $y$ (up or down)?

3. Aug 30, 2012

### Ry122

It is equal to the weight of the water displaced I believe.
But how can I form an equation of motion from this?

4. Aug 30, 2012

### gabbagabbahey

There are two forces acting on the cylinder at any given time:

(1) The downward force of gravity

(2) The buoyancy force (pressure) exerted by the water

Find a mathematical expression for the net force on the cylinder when it is displaced from equilibrium by a distance $y$

Newton's 2nd Law maybe?