Week 3: Bouyancy Flashcards
What is Archimedes Principle?
Archimedes Principle states that a body submerged in a fluid experiences an upward buoyant force equal to the weight of the fluid it displaces.
What is Bouyancy
Buoyancy is the upward force that acts on an object when it is submerged in a fluid. It is equal to the wieght of the fluid that the object displaces.
Equation For Buoyancy Force
F= Pw x G x Vw
How will an object float?
An object will float if the weight is equal to the buoyancy force.
How will an object sink?
An object will sink if the weight is greater than the buoyancy force.
How will an object rise?
An object will rise if the buoyancy force is greater than the weight.
What is Depth of Immersion and how do you find it?
Depth of Immersion is the vertical distance from the surface of a fluid to the submerged part of a floating object. Immersion (H) = Volume/Plan Area.
What is Centre Of Gravity?
Centre of Gravity is the point in a body where the total weight of the body is concentrated.
What is the Centre of Bouyancy?
Centre of Buoyancy is the centre of mass of the fluid that is displaced by a floating or submerged object. It is also the centroid of the immersed portion of a floating body.
What is Stability?
Stability is when a floating object tends to return to its og position after an angular displacement.
What is a Pontoon?
A pontoon is a watertight float or vessel used where buoyancy is required in water.
What is a Couple?
A couple is two equal parallel forces acting in opposite directions but not in the same line. A righting couple means a pair of forces that act in such a wat as to return the pontoon to its og position.
What is the Metacentre?
The Metacentre is where of the lines of centre of gravity and centre of buoyancy meet.
What is the Metacentric Height? (GM)
The Metacentric Height is the distance between a ship’s centre of gravity (G) and its metacentre (M), determining its stability in water.
Rules about M
-If M is above G, the pontoon is stable
-if M and G coincide (GM=0), then neutral stability exists so that if the pontoon is tilted it will continue to float with that exact tilt.
-If M is below G, the pontoon is unstable so if its tilted it will overturn.
What is Neutral Stability?
A state where a displaced object stays in its new position without returning to its original position or diverging further.
