Pressure & Depth
The _____ in a fluid increases with depth.
pressure
This upward force on an object submerged in a fluid equals the weight of the fluid displaced.
buoyant force
This type of substance is incompressible, meaning total flow in has to equal total flow out.
liquid
Temperature is a measure of the average __________ of particles in a substance.
This law relates pressure of a gas to its volume, temperature and number of particles.
ideal gas law
The weight of the air above us is responsible for _______ _______.
atmospheric pressure
If an object’s density is less than that of the fluid it is submerged in, it does this.
floats
In a pipe that narrows, the fluid’s speed does this.
speeds up
This type of heat transfer happens through direct molecular contact.
conduction
The more collisions there are between the particles of a confined gas and its surroundings, the _____ the pressure.
higher
If a fluid gets denser, what happens to the pressure acting within that fluid.
increases
This principle explains why a massive steel ship can float even though steel is denser than water.
Archimedes' Principle
According to Bernoulli’s principle, as the speed of a fluid increases, this property decreases.
pressure
The Sun warms Earth primarily through this method of heat transfer.
radiation
Scientists prefer this temperature scale for gas law calculations because it starts at absolute zero and has no negative values.
Kelvin
A block is submerged in a pool. The pressure acting on the underside of the block is ______ than the pressure acting at the block's top surface.
higher
The buoyant force equals the _____ of the _____ _____.
weight, fluid, displaced
Explain why some homes lose their roofs during a hurricane or tornado.
Key ideas: High wind speeds as air rushes over the tilted rood creates low pressure region above the roof. The air pressure inside the home then pushes the roof outwards.
Metals are called good thermal ________, while wood and air are examples of thermal ________.
conductors, insulators
The First Law of Thermodynamics states that the change in internal energy of a system equals heat added plus this quantity.
work done on the gas
Explain how you can drink water through a straw on Earth.
Key ideas: You remove air w/in straw to reduce pressure there, which allows atmospheric pressure to push down on water surface, forcing it up thru the straw.
A fully submerged object experiences a buoyant force that depends only on this property of the displaced fluid, not the object’s own weight.
its volume
What two things happen when the trajectory of 'flow lines' in a fluid bunch up?
the speed increases and the pressure drops
Explain why some surfaces in the same room can feel like they are cooler/warmer than other surfaces even when they are at the same temperature.
Key ideas: Different materials transfer the heat towards/away from your hand more/less effectively. This means metals pull energy from your hand faster than plaster walls might, resulting in the metal feeling cooler to the touch.
According to the 2nd Law of Thermodynamics, this quantity always increases for natural processes.
entropy