Buoyancy
This is the tendency for materials to rise or float in a fluid.
Buoyancy
water can support objects that have densities greater than water — as long as what condition is met?
.
the weight of the object is spread over a large enough area
The buoyant force of air is much smaller than the buoyant force of ______
water.
He believed that the displaced fluid held the key to whether the object placed in the fluid would sink or float.
Archimedes
The relationship between buoyancy and density is the basis for the _______ an instrument designed to measure liquid density.
hydrometer,
I am the upward force exerted on objects submerged in fluids. What am I?
a buoyant force
the total mass of all substances on board divided by the total volume would give me this
average density
Most fish have an organ called a what?
swim bladder (also called an air bladder).
When gravity equals buoyancy, this condition is known as
neutral buoyancy.
A block of an unknown metal measures 5 cm x 3 cm x 2 cm. The block has a mass of 235 g. Of what metal do you think the block is made? Would this metal sink in mercury?
Density=235 g/30 cm3=7.83 g/cm3
Iron: ~7.87 g/cm³
Mercury has a density of ~13.6 g/cm³, which is much higher than iron’s density. Since the block’s density is lower, it would float in mercury!
The transportation of nutrients through our bloodstream, pollen floating in the air, and boats and planes moving around the world would not be possible without this.
buoyant force.
Life jackets lower a person’s average _______ allowing the person to float.
density,
The swim bladder contains a mixture of air and water. Where is it located?
a large sac near the spine of the fish,
The buoyant force acting on an object equals the weight (force of gravity) of the fluid displaced by the object. This is known as?
Archimedes’ principle:
If the buoyant force equals the object’s weight, what will happen to the object?
it will neither sink nor rise—it will remain floating at a constant level in the fluid.
This occurs when an object does not fall in air or sink in water, but remains suspended in the fluid.
Floating
The Dead Sea contains many salts. Its density is great enough for people to _____ effortlessly on its surface.
float
Why can an airship such as a blimp can float ?
because its mass is relatively small compared to its enormous volume.
The buoyant force does not depend on the weight of the submerged object, but rather on this?
the weight of the displaced fluid.
Give an example of what can happen when the buoyant force on an object is greater than the weight of the object
When the buoyant force on an object is greater than its weight, the object will rise and float to the surface of the fluid
Like all other forces, buoyant force is measured in _________
newtons (N).
Average density is useful because
it enables objects that would otherwise sink — such as large ships and oil rigs — to float.
What is the most important design features of a hydrometer?
The graduated scale is the most important feature of a hydrometer because it allows users to accurately measure the density or specific gravity of a liquid
A solid cube of aluminum, a solid cube of iron, and a hollow cube of iron, all of the same volume, would experience the _____ buoyant force!
same
Explain how you could make plastic sink and steel float.
To make plastic sink, we need to increase its density Plastic- Fill it with a denser material
To make steel float, we need to decrease its effective density: shaping it into a hollow structure