Floating and Sinking Objecgts Flashcards
TRUE or FALSE - The overall average density of a substance is the density of the object itself and anything that is in or on it.
TRUE
An object that is more dense than the fluid it’s in will _____.
sink
An object that is less dense than the fluid it’s in will
float
By adding material onto an object, can increase or decrease its overall average density to change whether it sinks or floats.
both! By adding material to an object, you can increase or decrease its overall average density to change whether it sinks or floats.
How does a fish swim blatter work?
Fish float by filling their swim bladder with air, making them less dense than water. To sink, they release the air from their swim bladder to become denser than water.
How are submaries similar to fish?
Submarines use ballast tanks to control their buoyancy. They fill them with air to float and with water to sink. To stay at a certain depth, they fill the tanks with a mix of air and water to match the water’s density.
What is buoyancy?
Buoyancy is the ability of an object to float in a fluid.
How will an object float?
An object will float if it can displace an amount of fluid that weighs more than the object itself. This can be achieved by changing the shape (ex: clay ball vs clay boat) and/or density of the object
What is another word for positive bouyancy?
Floating
When does positive buoyancy occur?
Floating occurs when an object is less dense than the fluid, therefore displacing an amount of water that weighs more than itself
What does nutural bouyancy mean?
An object floating in the middle of a fluid
When does neutral buoyancy occur?
Neutral buoyancy (an object floating in the middle of a fluid) occurs when an object’s density is equal to the fluid, therefore displacing an amount of fluid that weighs the same amount as the object.
What does negative buoyancy mean?
sinking
When does negative buoyancy occur?
Negative buoyancy occurs when an object is denser than the fluid, therefore displacing an amount of water that weighs less than itself.
In order for an object to displace an amount of fluid heavier than its own weight, it must also be less dense than the fluid it’s in - why?
This is because the volume of the displaced fluid is equal to the volume of the submerged portion of the object. But, since the fluid is more dense than the object, the displaced volume has more mass (and weight) than the object, therefore causing the buoyant force to be stronger than the gravity.
