1. Buoyancy
What is buoyancy?
The ability to float.

2. What is buoyancy? Buoyancy The ability to float.
“Any body wholly or partially immersed in a fluid experiences an upthrust equal to, but opposite in sense to, the weight of the fluid displaced.”
Archimedes Principle
The ability to float.

3. Forces in Action Buoyancy The ability to float.
Buoyancy: upward force on an object
Gravity: downward force on an object
Pressure: force all around an object
Gravity
The ability to float.
Pressure
Pressure
Buoyancy

4. Finding the Balance Buoyancy The ability to float.
When there is a balance between the buoyant force and the force of gravity the object is said to be neutrally buoyant.
The key is to make an ROV that is as close to neutrally buoyant as possible, or the buoyant force should be slightly more than the force of gravity (to prevent sinking).
The ability to float.

5. Types of Buoyancy Buoyancy Positively Buoyant Neutrally Buoyant
Negatively Buoyant

6. Buoyancy
Ballast
Dynamic (soft): system that changes the amount of water displace inside the ballast chamber.
Static: ballast chamber does not change. ROV is designed to be neutrally buoyant and motors move it up and down. The volume of air stays the same.

7. Balance Center of Mass Build an ROV Interactive:
Knowing the center of mass for a car, for example, is enough to estimate whether it can be tipped over by maneuvers
on level ground. The center of mass of a boat must be low enough for the boat to be
stable. Any propulsive force on a space craft must be directed towards the center of
mass in order to not induce rotations. Tracking the trajectory of the center of mass of
an exploding plane can determine whether or not it was hit by a massive object. Any
rotating piece of machinery must have its center of mass on the axis of rotation if it
is not to cause much vibration.

8. Frame Construction
Buoyancy and Balance
Let’s do an experiment!

9. Let’s make this positively, neutrally, and negatively buoyant!
Frame Construction
Buoyancy and Balance
Let’s make this float!
Let’s make this positively, neutrally, and negatively buoyant!