Pressure Flashcards
What is pressure?
Pressure is the force acting per unit of area
1Pa = 1N/m^2
What is a fluid?
Either a liquid or a gas
How does pressure act on the surfaces?
The pressure in fluids causes a normal force at right angles to any surface
Or
The humongous weight of your mum.
What affects the pressure of a FLUID?
Temperature, volume and depth
What are the two equations for pressure in a fluid?
P = M / V
P = ρgh
need to understand how straws work
.
Which direction does air pressure act in?
All directions
What is atmospheric pressure at sea level?
101 kPa
What is the density of water?
997 kg/m^3
What are barometers used to measure?
Atmospheric Pressure
What does a manometer measure?
Difference n Pressure
What is Upthrust?
An upward force exerted by any fluid that opposes the weight of an immersed object
Why do things rise in a fluid?
If the upthrust is greater than the weight of the object
When does an object sink?
If the density of the object is greater than the density of the fluid, the object can never displace enough fluid to create an upthrust that will hold its weight so it SINKS
When do objects float?
When its weight is equal to the upthrust
What is Archimedes Principle?
When an object is partially of fully immersed in a fluid, the fluid exerts an upward force on the object equal to the weight of the fluid displaced
How can pressure be compared to Vol?
For a given mass at a constant temperature, the pressure is INVERSELY PROPORTIONAL to the volume.
how can we describe the motion of the particles of a gas?
The particles more RANDOMLY
What happens to a gas if the temperature is increased?
When there is a higher temperature, the pressure of the gas increases because they hit surfaces with higher force, so the number of impacts per second INCREASES, so the total force of impact increases
What happens when one reduces the volume of a gas?
Impacts per second increases which increases the pressure
How does compressing the gas affect the temperature?
Temperature increases when the gas is compressed because when compressing it does work on it and energy isn’t transferred quickly enough to the surroundings therefore it heats up
What is Charles’ law?
As you increase temperature, the volume increases too.
They are directly proportional.
What is Boyle’s Law?
As you increase pressure volume decreases
