Pressure, Density And Force Flashcards
What is pressure?
Force per unit area (P = F/A)
What are the units for pascals (Pa)
N/m^2
Are area and force directly or inversly proportional?
Inversly proportional (smaller area = larger force)
What formula would you use for measuring the pressure of the bottom of a tank?
P= F/A
What formula would you use to measure the overall liquid pressure of a tank?
P=d x h x g
Turn 1g/cm^3 into kg/m^3?
1 x 1000 = 1000 kg/m^3
What would you do to calculate total pressure of a substance?
Total p = liq pressure (hdg) + atmospheric pressure (1.01 x 10^5 N/m^2)
What would you do to calculate total pressure of a substance?
Total p = liq pressure (hdg) + atmospheric pressure (1.01 x 10^5 N/m^2)
Why is the maximum drinking length of a straw 10.1m?
When sucking up water in a straw it causes a vaccum aboth the water, hensforth making the pressure pushing the water up a certain amount.
What causes a liquid to go up a straw?
The difference in air pressure (atmospheric pressure and pressure in your mouth)
What is a manomiter?
It is a pressure difference device?
How do gasses exert pressure?
Gasses exert pressure due to collisions of particals against the wall of a container
What is an equation for gas pressure?
Pressure = collissions (F)/ volume of tank(A)
What are some factors that affect size of gas pressure?
Number of atoms
Temperature of gas
Volume of container
As the temperature rises the pressure rises, why?
When the temp rises so does the average kinetic energy of the particals, therefore the collisions/sec happens at a higher rate on the wall of the container. This causes more pressure.
As the volume increases, the pressure decreases, why?
When the volume increases the pressure lowers, this is due to the particals colliding with the walls of the container at a lower rate, therefore meaning there is less pressure formed.
What happens to the force when the volume of a container (containing gas) is halved?
The force doubles
Two air bubbles are formed in the same body of water. They have two different volumes and pressures but they are both contained in the same body, why is this possible?
F1 x V1 = F2 x V2
EG. 300000Pa x 2cm^2 = 100000Pa x 6cm^2
Or volume x pressure = constant
What is density?
Mass per unit volume
What is an equation for density?
density (d) = mass (g) / volume (m^3)
What is a vernicalliber?
A device usedbto measure things by the 100th mm
What is a baromiter?
An instrument measuring atmospheric pressure, used especially in forecasting the weather and determining altitude.
What can be barometers be used for?
Measuring weather and temperature
How does a barometer work?
A barometer acts like a balance that ‘balances’ the weight of the atmosphere (or air around you) against the weight of a mercury column.
The air pressure pushes up into a vaccume above the mercury.
If the air pressure is high, the mercury will rise. At low air pressure, the mercury goes down.
